Tailwind doesn't provide `hyphens` utility classes out of the box. We
should follow up by investigating whether we really want to enable
hyphenation and what the current support landscape is for hyphenation.

Previously the arguments of the callback passed to `PortRPC.on` were
inferred as `any`. Make the callback type generic so that the caller is
forced to specify what types the arguments have.

Internally within PortRPC, use `unknown` rather than `any` for RPC
method arguments where possible.

Note that this change does not ensure that an RPC method is called (via `call`)
using arguments of the same types that the handler expects, but at least it is
now easier to check that the `call` and `on` uses match up and that arguments
are typed within the handler.

Update a few components to account for style adjustments

The `Menu` container element was stretching to fill the entire grid
slot, which made the little menu "caret" show up too far to the right
when the menu was opened.

Bumps [eslint](https://github.com/eslint/eslint) from 8.14.0 to 8.15.0.
- [Release notes](https://github.com/eslint/eslint/releases)
- [Changelog](https://github.com/eslint/eslint/blob/main/CHANGELOG.md)
- [Commits](https://github.com/eslint/eslint/compare/v8.14.0...v8.15.0)

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updated-dependencies:
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  dependency-type: direct:development
  update-type: version-update:semver-minor
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Bumps [sinon](https://github.com/sinonjs/sinon) from 13.0.2 to 14.0.0.
- [Release notes](https://github.com/sinonjs/sinon/releases)
- [Changelog](https://github.com/sinonjs/sinon/blob/main/docs/changelog.md)
- [Commits](https://github.com/sinonjs/sinon/compare/v13.0.2...v14.0.0)

---
updated-dependencies:
- dependency-name: sinon
  dependency-type: direct:development
  update-type: version-update:semver-major
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Bumps [rollup](https://github.com/rollup/rollup) from 2.71.1 to 2.72.1.
- [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/v2.71.1...v2.72.1)

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updated-dependencies:
- dependency-name: rollup
  dependency-type: direct:development
  update-type: version-update:semver-minor
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Bumps [preact](https://github.com/preactjs/preact) from 10.7.1 to 10.7.2.
- [Release notes](https://github.com/preactjs/preact/releases)
- [Commits](https://github.com/preactjs/preact/compare/10.7.1...10.7.2)

---
updated-dependencies:
- dependency-name: preact
  dependency-type: direct:development
  update-type: version-update:semver-patch
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Bumps [npm-packlist](https://github.com/npm/npm-packlist) from 5.0.2 to 5.0.3.
- [Release notes](https://github.com/npm/npm-packlist/releases)
- [Changelog](https://github.com/npm/npm-packlist/blob/main/CHANGELOG.md)
- [Commits](https://github.com/npm/npm-packlist/compare/v5.0.2...v5.0.3)

---
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- dependency-name: npm-packlist
  dependency-type: direct:development
  update-type: version-update:semver-patch
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Bumps [core-js](https://github.com/zloirock/core-js) from 3.22.3 to 3.22.4.
- [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/v3.22.3...v3.22.4)

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- dependency-name: core-js
  dependency-type: direct:development
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Bumps [aws-sdk](https://github.com/aws/aws-sdk-js) from 2.1125.0 to 2.1130.0.
- [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/v2.1125.0...v2.1130.0)

---
updated-dependencies:
- dependency-name: aws-sdk
  dependency-type: direct:development
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Bumps [autoprefixer](https://github.com/postcss/autoprefixer) from 10.4.6 to 10.4.7.
- [Release notes](https://github.com/postcss/autoprefixer/releases)
- [Changelog](https://github.com/postcss/autoprefixer/blob/main/CHANGELOG.md)
- [Commits](https://github.com/postcss/autoprefixer/compare/10.4.6...10.4.7)

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`@return` is much more widely used in the codebase.

The `compare` and `callback` arguments were swapped during earlier
development, but the examples were not updated to match.

The anchoring implementation is now part of the `Integration` which
guests create.

Clarify why `fitSideBySide` is re-run and why the `html_side_by_side`
flag is forcibly enabled for VS.

Enable support for side-by-side mode for all web pages, behind an
`html_side_by_side` feature flag.

 - Add `html_side_by_side` flag to known flags in `features.js`

 - Define `FeatureFlags` interface for querying (but not updating flags)
   and make the `FeatureFlags` class implement it

 - Pass the `FeatureFlags` instance from Guest through to
   HTMLIntegration and read/observe the `html_side_by_side` flag to
   enable/disable side-by-side mode

 - Create a dummy `FeatureFlags` implementation in
   `VitalSourceContentIntegration` which always has the
   `html_side_by_side` flag turned on

This encourages reading of specific flags to be done via `flagEnabled`, which
checks for usage of unknown flags.

Rewrite the infrastructure that sends feature flags to annotator code, to
support feature-flagging functionality in guest frames, instead of just the host
frame.

 - Remove `FeaturesService` in the sidebar and move the logic for
   syncing feature flags from the sidebar to other frames into
   `FrameSyncService`.  This is a better place since `FrameSyncService`
   knows when frames connect and thus when to send flags to them. The
   logic for monitoring for flag changes is very simple and doesn't
   needs its own service.

 - Within `FrameSyncService`, send "featureFlagsUpdated" notifications to
   both host frames and guest frames.

 - Convert the functions and global variables in `annotator/features.js`
   into a `FeatureFlags` class, which encapsulates storage of flags,
   access to them and notifying consumers when flags change.

 - Instantiate `FeatureFlags` instances in the host frame and guest
   frame and update the flags stored in them when "featureFlagsUpdated" events
   are received from the sidebar.

 - Rename `getElement` => `findElementByTestId` for clarity
 - Eliminate unnecessary `context` blocks in `MarkdownEditor` tests
 - Narrow scope of `console.warn` suppression in `useArrowKeyNavigation`
   test
 - Explain why keyboard navigation tests do not use Enzyme

Extract the arrow key navigation logic from `MarkdownEditor` into a
reusable `useArrowKeyNavigation` navigation hook. This simplifies the
MarkdownEditor component and will allow us to enable arrow key
navigation more widely thoughout the application.

A notable design choice is that the roving tab index state lives in the DOM
rather than in Preact. This enables the Preact component-facing API to be very
simple: a single hook call in the component that renders the container element
(of the toolbar, menu bar etc.). It does mean however that the `tabIndex` state
is not accessible to components. This works for the use cases where I have
tested it, but we may need to revisit in future.

If browsers add a native feature to handle this in future [1], the hook
could handle testing for support and using it where available.

 - Create `useArrowKeyNavigation` navigation hook in
   `src/shared/keyboard-navigation.js` as a general method of adding
   arrow key navigation to a composite widget

 - Modify `MarkdownEditor` to use the `useArrowKeyNavigation` hook to
   handle arrow key navigation

 - Replace detailed tests for arrow key navigation in `MarkdownEditor`
   with more basic tests, as the `useArrowKeyNavigation` tests cover the
   general functionality in detail

[1] eg. https://github.com/MicrosoftEdge/MSEdgeExplainers/blob/main/Focusgroup/explainer.md

Enable the `ListenerCollection.add` method to know the specific type of
event that a listener will receive, based on the event target and event
name. This simplifies usage by removing the need to cast the argument in
most cases.

The implementation relies on the target having an `on${eventName}`
property from which the event type can be extracted. If it doesn't, it
will fall back to `Event`.

This includes the results of RPC calls to the LMS app, which must now be
explicitly cast to the expected result type.

Use `AnnotationHeader` directly

The issue has been fixed upstream, but we need to keep the workaround
for old versions of PDF.js with Hypothesis embedded, that still exist on
various websites.

This comment was written prior to the change to draw highlights in an
SVG in PDFs.

Remove obsolete fallback for browsers that don't support mix-blend-mode.
All of our current targets do, per https://caniuse.com/mdn-css_properties_mix-blend-mode.