Adding automated a11y tests for Canvas

[myasonik]

Summary

Fixing some a11y issues on the Canvas landing page while writing some automated tests for it as a demo.

(demo for the curious)

Specific changes

• Added a column title to Actions (mimicking other pages such as Dashboards and Visualizations)
• Wrapped the page title in an <h1>
• Added an aria-label for the CVS upload <input />
• Added a bunch of data-test-subj to be able to write tests

Checklist

Delete any items that are not applicable to this PR.

• Any text added follows EUI's writing guidelines, uses sentence case text and includes i18n support
• [ ] Documentation was added for features that require explanation or tutorials
• [ ] Unit or functional tests were updated or added to match the most common scenarios
• Any UI touched in this PR is usable by keyboard only (learn more about keyboard accessibility)
• Any UI touched in this PR does not create any new axe failures (run axe in browser: FF, Chrome)
• [ ] If a plugin configuration key changed, check if it needs to be allowlisted in the cloud and added to the docker list
• [ ] This renders correctly on smaller devices using a responsive layout. (You can test this in your browser)
• [ ] This was checked for cross-browser compatibility

For maintainers

• This was checked for breaking API changes and was labeled appropriately

[elasticmachine]

Pinging @elastic/kibana-presentation (Team:Presentation)

[elasticmachine]

Pinging @elastic/kibana-accessibility (Project:Accessibility)

[kibanamachine]

💚 Build Succeeded

• continuous-integration/kibana-ci/pull-request
• Commit: a4acb29

Metrics [docs]

Async chunks

Total size of all lazy-loaded chunks that will be downloaded as the user navigates the app

id	before	after	diff
canvas	1.4MB	1.4MB	+332.0B

Page load bundle

Size of the bundles that are downloaded on every page load. Target size is below 100kb

id	before	after	diff
canvas	591.8KB	592.0KB	+262.0B

History

• 💔 Build #107037 failed 8bce550

To update your PR or re-run it, just comment with:
@elasticmachine merge upstream

[cqliu1]

LGTM 👍 Thanks for adding these a11y tests!

[kibanamachine]

💚 Backport successful

✅ 7.x / #91893

Successful backport PRs will be merged automatically after passing CI.