When rendering math, the custom KaTex fonts failed to load due to the
relative URL references in `build/styles/katex.min.css` not matching the
actual location of the fonts in `build/fonts`. The KaTeX CSS assumes a
URL structure like:

```
katex.min.css
fonts/
  KaTeX_AMS-Regular.woff2
```

Previously font URLs in katex.min.css were rewritten from
`url('fonts/foo.woff2')` to `url('../fonts/foo.woff2')` by a PostCSS
plugin when building the CSS bundles. However this got lost when
replacing the client's local style-bundling script with the one from the
@hypothesis/frontend-shared package.

By relocating the fonts to a subdirectory of `build/styles` we can make
the asset references work without needing to do any rewriting of URLs in
the KaTeX CSS bundle.

In the process, the list of fonts included in the bundle was simplified
to include just WOFF2 fonts, since all modern browsers support that
format. Additionally an obsolete reference to fonts in src/styles/vendor
was removed.

The change to load the annotator bundle as a JS module script rather
than a classic script broke re-loading of the client, eg. when toggling
the browser extension on and off in a page. This is because module scripts are
only evaluated the first time that they are loaded in a page, unlike
classic scripts. This prevented the annotator entry module
(src/annotator/index.js) from re-running when the client was reloaded.

It turns out that it is possible to force re-evaluation of module
scripts without a negative impact on browser or CDN caching by appending
a dynamic fragment to the script URL. This commit applies this technique
to force re-evaluation of all module scripts added to the host page by
the boot script.

Bumps [rollup](https://github.com/rollup/rollup) from 2.58.0 to 2.58.3.
- [Release notes](https://github.com/rollup/rollup/releases)
- [Changelog](https://github.com/rollup/rollup/blob/master/CHANGELOG.md)
- [Commits](https://github.com/rollup/rollup/compare/v2.58.0...v2.58.3)

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Bumps [postcss](https://github.com/postcss/postcss) from 8.3.9 to 8.3.11.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](https://github.com/postcss/postcss/compare/8.3.9...8.3.11)

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Bumps [karma](https://github.com/karma-runner/karma) from 6.3.4 to 6.3.5.
- [Release notes](https://github.com/karma-runner/karma/releases)
- [Changelog](https://github.com/karma-runner/karma/blob/master/CHANGELOG.md)
- [Commits](https://github.com/karma-runner/karma/compare/v6.3.4...v6.3.5)

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Bumps [aws-sdk](https://github.com/aws/aws-sdk-js) from 2.1010.0 to 2.1013.0.
- [Release notes](https://github.com/aws/aws-sdk-js/releases)
- [Changelog](https://github.com/aws/aws-sdk-js/blob/master/CHANGELOG.md)
- [Commits](https://github.com/aws/aws-sdk-js/compare/v2.1010.0...v2.1013.0)

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Bumps [@rollup/plugin-node-resolve](https://github.com/rollup/plugins/tree/HEAD/packages/node-resolve) from 13.0.5 to 13.0.6.
- [Release notes](https://github.com/rollup/plugins/releases)
- [Changelog](https://github.com/rollup/plugins/blob/master/packages/node-resolve/CHANGELOG.md)
- [Commits](https://github.com/rollup/plugins/commits/node-resolve-v13.0.6/packages/node-resolve)

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Bumps [@hypothesis/frontend-build](https://github.com/hypothesis/frontend-build) from 1.0.1 to 1.1.0.
- [Release notes](https://github.com/hypothesis/frontend-build/releases)
- [Changelog](https://github.com/hypothesis/frontend-build/blob/main/CHANGELOG.md)
- [Commits](https://github.com/hypothesis/frontend-build/compare/v1.0.1...v1.1.0)

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Bumps [commander](https://github.com/tj/commander.js) from 8.2.0 to 8.3.0.
- [Release notes](https://github.com/tj/commander.js/releases)
- [Changelog](https://github.com/tj/commander.js/blob/master/CHANGELOG.md)
- [Commits](https://github.com/tj/commander.js/compare/v8.2.0...v8.3.0)

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Bumps [@rollup/plugin-commonjs](https://github.com/rollup/plugins/tree/HEAD/packages/commonjs) from 21.0.0 to 21.0.1.
- [Release notes](https://github.com/rollup/plugins/releases)
- [Changelog](https://github.com/rollup/plugins/blob/master/packages/commonjs/CHANGELOG.md)
- [Commits](https://github.com/rollup/plugins/commits/commonjs-v21.0.1/packages/commonjs)

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Bumps [sass](https://github.com/sass/dart-sass) from 1.43.2 to 1.43.3.
- [Release notes](https://github.com/sass/dart-sass/releases)
- [Changelog](https://github.com/sass/dart-sass/blob/main/CHANGELOG.md)
- [Commits](https://github.com/sass/dart-sass/compare/1.43.2...1.43.3)

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Bumps [@rollup/plugin-alias](https://github.com/rollup/plugins/tree/HEAD/packages/alias) from 3.1.5 to 3.1.8.
- [Release notes](https://github.com/rollup/plugins/releases)
- [Changelog](https://github.com/rollup/plugins/blob/master/packages/alias/CHANGELOG.md)
- [Commits](https://github.com/rollup/plugins/commits/alias-v3.1.8/packages/alias)

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Bumps [core-js](https://github.com/zloirock/core-js) from 3.18.3 to 3.19.0.
- [Release notes](https://github.com/zloirock/core-js/releases)
- [Changelog](https://github.com/zloirock/core-js/blob/master/CHANGELOG.md)
- [Commits](https://github.com/zloirock/core-js/compare/v3.18.3...v3.19.0)

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Update lint config for .mjs files and remove unused variables in
gulpfile.mjs.

See also https://github.com/hypothesis/frontend-shared/pull/215.

There are two type of events:

* command events (`openSidebar`, `closeSidebar`): direct the receiving
  frame to take an specific action.

* information events ('sidebarOpened`, `helpRequested`): informs the
  receiving frame that an action _already_ took place, in case a follow
  up action needs to happen.

The `destroyFrame` aligns more with the second type.

Follow up of: https://github.com/hypothesis/client/pull/3838/files#r731077947

The new name reflects more obviously the meaning the purpose of the
event.

This is the event that creates the annotation, so it is better to name
it in a more obvious way.

Context:
https://github.com/hypothesis/client/pull/3829#discussion_r726880585

Change the logic for making highlights visible when creating a new
annotation, so that it works if the annotation was created in a non-host
frame.

This is done by moving the logic from the `beforeAnnotationCreated`
handler in the Sidebar class, which was only called for annotations in
the host frame, to the `beforeCreateAnnotation` handler in
FrameSyncService, which is called for all frames. The sidebar app will
then send a request to show highlights to the host frame, which will
update the sidebar's controls and then relay the request to guest
frames.

Make the client's highlight visibility state work in a sane way in
scenarios where there are multiple guests, or the main guest frame is not the
host frame. Previously there were several problems in these scenarios:

 - It was unclear which component of the application "owned" the
   highlight visibility state. The state in the sidebar could be changed
   as a result of the `highlightsVisibleChanged` event emitted by a
   Guest, as well as the user toggling highlight controls in the
   sidebar.

 - In the sidebar's `open` and `close` methods it directly set the
   highlight visibility in the main guest if the `showHighlights`
   setting was set to `whenSidebarOpen`. This meant that it didn't work
   for guests that were not in the main frame.

 - Guest frames could be configured with different `showHighlights`
   settings. In this case it was unclear what should happen.

This commit resolves this by making the `Sidebar` class in the host
frame the central owner of this state. It handles configuring the
initial state based on the `showHighlights` configuration setting, and
reflecting this state to the sidebar application which in turn reflects
it to guest frames. The initial visibility of highlights in a guest
frame is synchronized with this state when the guest frame connects to
the sidebar. This state is updated by the `Sidebar` class when:

 - The user toggles the highlight visibility control in the sidebar
 - A new highlight or annotation is created in a guest frame
 - The sidebar opens and closes, if the `showHighlights` configuration
   was set to `whenSidebarOpen`

Additionally the inconsistency of `setHighlightsVisible` vs
`setVisibleHighlights` in identifier and event names has been resolved by
using `setHighlightsVisible`/`highlightsVisible` everywhere.

Part of https://github.com/hypothesis/client/issues/3798

There was an action to set this state but it was never read anywhere.

Co-authored-by: Robert Knight <robertknight@gmail.com>

I have created type definitions for all the event names that are sent
across the different frames using various `Bridge`s. It is based on the
previous `bridge-events.js`. I broke down the events in four sections
based on the direction of the messages:

* guest -> sidebar events
* host -> sidebar events
* sidebar -> guest/s events
* sidebar -> host events

For those events that didn't have a description I added one.

This is more stringent and less verbose than the previous lookup system.

Move the responsibility for opening the sidebar when there is a draft to
edit from the guest into the sidebar's `FrameSyncService`.

The initial motivation for this was to make the logic in the
`beforeAnnotationCreated` event handler in the `Sidebar` class work if
the annotation is created in a non-host guest frame. The plan was to
make the sidebar send an `openSidebar` request with custom options that
would trigger the logic that used to be in the `beforeAnnotationCreated`
event handler.

However it appears that focusing the sidebar frame is no longer necessary. In my
testing the input field in the sidebar was successfully focused regardless
of whether `iframe.contentWindow.focus()` was called or not. Therefore I
have just removed the handler.

Even though the original need no longer exists, moving the logic still
seems sensible because logically it is the sidebar application that
knows it is awaiting user input after a new draft is created. It also means that
if we do find a need to re-introduce the frame-focusing logic that used
to be in the `beforeAnnotationCreated` handler, we can do so in a way
that works with annotations created in non-host frames.

The initial un-hiding and opening of the sidebar was previously
triggered by a `panelReady` event emitted by the Guest in the host frame
when it connects.

As part of eliminating the need for the host frame to also be a guest,
change the initial sidebar open to use the `Sidebar.ready` promise
instead, which is resolved when the sidebar applicaiton sends a
`hypothesisSidebarReady` notice to the `Sidebar` app.

Part of https://github.com/hypothesis/client/issues/3798

Fix `gulp test --watch`. See https://github.com/hypothesis/frontend-shared/pull/214.

Streamline the Karma configuration to remove obsolete settings and make
it easier to see what non-default configuration we have supplied.

 - Remove `grep` option handling. The `--grep` option when running tests
   is now used in gulpfile.js to select which _files_ are included in
   the test.

 - Remove comments which add little value

 - Remove config settings that just set default values which are not
   expected to change in future

Bumps [rollup](https://github.com/rollup/rollup) from 2.47.0 to 2.58.0.
- [Release notes](https://github.com/rollup/rollup/releases)
- [Changelog](https://github.com/rollup/rollup/blob/master/CHANGELOG.md)
- [Commits](https://github.com/rollup/rollup/compare/v2.47.0...v2.58.0)

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Bumps [babel-plugin-istanbul](https://github.com/istanbuljs/babel-plugin-istanbul) from 6.0.0 to 6.1.1.
- [Release notes](https://github.com/istanbuljs/babel-plugin-istanbul/releases)
- [Changelog](https://github.com/istanbuljs/babel-plugin-istanbul/blob/master/CHANGELOG.md)
- [Commits](https://github.com/istanbuljs/babel-plugin-istanbul/compare/v6.0.0...v6.1.1)

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  dependency-type: direct:development
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Bumps [@rollup/plugin-commonjs](https://github.com/rollup/plugins/tree/HEAD/packages/commonjs) from 19.0.0 to 21.0.0.
- [Release notes](https://github.com/rollup/plugins/releases)
- [Changelog](https://github.com/rollup/plugins/blob/master/packages/commonjs/CHANGELOG.md)
- [Commits](https://github.com/rollup/plugins/commits/commonjs-v21.0.0/packages/commonjs)

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  dependency-type: direct:development
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Bumps [aws-sdk](https://github.com/aws/aws-sdk-js) from 2.1004.0 to 2.1010.0.
- [Release notes](https://github.com/aws/aws-sdk-js/releases)
- [Changelog](https://github.com/aws/aws-sdk-js/blob/master/CHANGELOG.md)
- [Commits](https://github.com/aws/aws-sdk-js/compare/v2.1004.0...v2.1010.0)

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Bumps [@rollup/plugin-node-resolve](https://github.com/rollup/plugins/tree/HEAD/packages/node-resolve) from 13.0.0 to 13.0.5.
- [Release notes](https://github.com/rollup/plugins/releases)
- [Changelog](https://github.com/rollup/plugins/blob/master/packages/node-resolve/CHANGELOG.md)
- [Commits](https://github.com/rollup/plugins/commits/node-resolve-v13.0.5/packages/node-resolve)

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Bumps [mocha](https://github.com/mochajs/mocha) from 9.1.2 to 9.1.3.
- [Release notes](https://github.com/mochajs/mocha/releases)
- [Changelog](https://github.com/mochajs/mocha/blob/master/CHANGELOG.md)
- [Commits](https://github.com/mochajs/mocha/compare/v9.1.2...v9.1.3)

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Bumps [sass](https://github.com/sass/dart-sass) from 1.42.1 to 1.43.2.
- [Release notes](https://github.com/sass/dart-sass/releases)
- [Changelog](https://github.com/sass/dart-sass/blob/main/CHANGELOG.md)
- [Commits](https://github.com/sass/dart-sass/compare/1.42.1...1.43.2)

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Bumps [@rollup/plugin-alias](https://github.com/rollup/plugins/tree/HEAD/packages/alias) from 3.1.2 to 3.1.5.
- [Release notes](https://github.com/rollup/plugins/releases)
- [Changelog](https://github.com/rollup/plugins/blob/master/packages/alias/CHANGELOG.md)
- [Commits](https://github.com/rollup/plugins/commits/alias-v3.1.5/packages/alias)

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Bumps [typescript](https://github.com/Microsoft/TypeScript) from 4.4.3 to 4.4.4.
- [Release notes](https://github.com/Microsoft/TypeScript/releases)
- [Commits](https://github.com/Microsoft/TypeScript/compare/v4.4.3...v4.4.4)

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Bumps [core-js](https://github.com/zloirock/core-js) from 3.18.2 to 3.18.3.
- [Release notes](https://github.com/zloirock/core-js/releases)
- [Changelog](https://github.com/zloirock/core-js/blob/master/CHANGELOG.md)
- [Commits](https://github.com/zloirock/core-js/compare/v3.18.2...v3.18.3)

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