Prepare for transition to ES modules

Add `title` property to `SvgIcon`

Fix incorrect attribute type

Optional property `title` sets `title` on SVG’s containing `span` for
a11y/usability

In preparation for converting the client source to ES modules, in order
that the pattern library and other frontend apps all use the same module
system, change the source type for ESLint to "module" and remove the
"use strict" declarations at the top of each source file.

Babel already inserts "use strict" at the top of every module it
processes and support for transpiling ES modules is already enabled by
@babel/preset-env.

The change is only applied to modules in `src/` as build scripts
(gulpfile.js, `scripts/**.js`) are not treated as modules.

Fix focus halo on primary action button mixin

Update and Simplify `SelectionTabs`, `NewNoteButton` icons, styling

- Convert `annotate` icon in `SelectionTabs` to SVG
- Remove redundant/misleading `note` icon from `SelectionTabs`
- Remove tutorial-display conditional from `SelectionTabs`
- Remove excess SASS rules from `SelectionTabs`

Bump postcss from 7.0.24 to 7.0.26

Bumps [postcss](https://github.com/postcss/postcss) from 7.0.24 to 7.0.26.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/master/CHANGELOG.md)
- [Commits](https://github.com/postcss/postcss/compare/7.0.24...7.0.26)
Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Bump sinon from 7.5.0 to 8.0.1

`sinon.sandbox.create()` was removed in favor of
`sinon.createSandbox()`. See https://sinonjs.org/releases/v8.0.2/sandbox/.

The API documentation suggests using a default sandbox for most cases
rather than creating a custom one. To keep the change here simple, I've
left the logic as it was before, but just adapted to the new API.

Bump scroll-into-view from 1.13.1 to 1.14.1

Bump npm-packlist from 2.0.2 to 2.0.3

Bump fetch-mock from 8.1.0 to 8.3.0

[Security] Bump handlebars from 4.1.2 to 4.5.3

Bump postcss from 7.0.24 to 7.0.25

Bumps [npm-packlist](https://github.com/npm/npm-packlist) from 2.0.2 to 2.0.3.
- [Release notes](https://github.com/npm/npm-packlist/releases)
- [Commits](https://github.com/npm/npm-packlist/compare/v2.0.2...v2.0.3)
Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Bump preact from 10.1.0 to 10.1.1

Bump babel-plugin-istanbul from 5.2.0 to 6.0.0

Bump terser from 4.4.2 to 4.4.3

Remove ng-tags-input dependency and unused tags-input styles

Use mobile-friendly font size for all input fields

- Post new annotation button no longer renders blue halo when clicked with a mouse, and only when tabbed to with keyboard
- Remove `primary-action-btn.scss`- was not  used since a mixin served same purpose.

Bumps [scroll-into-view](https://github.com/KoryNunn/scroll-into-view) from 1.13.1 to 1.14.1.
- [Release notes](https://github.com/KoryNunn/scroll-into-view/releases)
- [Commits](https://github.com/KoryNunn/scroll-into-view/commits)
Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Bumps [fetch-mock](https://github.com/wheresrhys/fetch-mock) from 8.1.0 to 8.3.0.
- [Release notes](https://github.com/wheresrhys/fetch-mock/releases)
- [Commits](https://github.com/wheresrhys/fetch-mock/compare/v8.1.0...v8.3.0)
Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Bumps [@octokit/rest](https://github.com/octokit/rest.js) from 16.35.2 to 16.36.0.
- [Release notes](https://github.com/octokit/rest.js/releases)
- [Commits](https://github.com/octokit/rest.js/compare/v16.35.2...v16.36.0)
Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Add userid key to config docs for focus mode

Bumps [handlebars](https://github.com/wycats/handlebars.js) from 4.1.2 to 4.5.3. **This update includes a security fix.**
- [Release notes](https://github.com/wycats/handlebars.js/releases)
- [Changelog](https://github.com/wycats/handlebars.js/blob/master/release-notes.md)
- [Commits](https://github.com/wycats/handlebars.js/compare/v4.1.2...v4.5.3)
Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Bumps [preact](https://github.com/preactjs/preact) from 10.1.0 to 10.1.1.
- [Release notes](https://github.com/preactjs/preact/releases)
- [Commits](https://github.com/preactjs/preact/compare/10.1.0...10.1.1)
Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Bumps [postcss](https://github.com/postcss/postcss) from 7.0.24 to 7.0.25.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/master/CHANGELOG.md)
- [Commits](https://github.com/postcss/postcss/compare/7.0.24...7.0.25)
Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Bumps [sinon](https://github.com/sinonjs/sinon) from 7.5.0 to 8.0.1.
- [Release notes](https://github.com/sinonjs/sinon/releases)
- [Changelog](https://github.com/sinonjs/sinon/blob/master/CHANGELOG.md)
- [Commits](https://github.com/sinonjs/sinon/compare/v7.5.0...v8.0.1)
Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Bumps [babel-plugin-istanbul](https://github.com/istanbuljs/babel-plugin-istanbul) from 5.2.0 to 6.0.0.
- [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/v5.2.0...v6.0.0)
Signed-off-by: dependabot-preview[bot] <support@dependabot.com>