[User Profile Settings] Implement toggle for high contrast mode

[tsullivan]

Summary

Closes #176219
Depends on #215698

EUI provides documentation about high contrast mode. This includes info about when it is enabled automatically, and some developer utilities. See: https://eui.elastic.co/#/theming/high-contrast-mode

Release note

Added an option to User Settings that allows the Kibana interface to display in a high contrast mode.

[elasticmachine]

Pinging @elastic/appex-sharedux (Team:SharedUX)

[elasticmachine]

Pinging @elastic/kibana-security (Team:Security)

[Dosant]

tiny suggestion to memo the observable, because now useObservable would unsubscribe and subscribe with every render

[tsullivan]

@Dosant I take it you mean we should call a memoized version of getUserProfile$. Is this what you mean?

-  const getUserProfile$ = userProfile?.getUserProfile$ ?? Rx.of;
+  const getUserProfile$ = useMemo(
+    () => userProfile?.getUserProfile$ ?? Rx.of,
+    [userProfile?.getUserProfile$]
+  );

[elasticmachine]

Pinging @elastic/kibana-core (Team:Core)

[gsoldevila]

The src/core/packages/overlays/browser-internal/src/modal/__snapshots__/modal_service.test.tsx.snap snapshot is crazy long and thus useless.

I'll improve the related test on a follow-up PR.

[elasticmachine]

💚 Build Succeeded

• Buildkite Build
• Commit: 0ce03d3

Metrics [docs]

Public APIs missing comments

Total count of every public API that lacks a comment. Target amount is 0. Run node scripts/build_api_docs --plugin [yourplugin] --stats comments for more detailed information.

id	before	after	diff
@kbn/user-profile-components	21	23	+2

Async chunks

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

id	before	after	diff
security	514.1KB	515.6KB	+1.5KB

Page load bundle

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

id	before	after	diff
kbnUiSharedDeps-srcJs	3.6MB	3.6MB	+320.0B

Unknown metric groups

API count

id	before	after	diff
@kbn/user-profile-components	81	83	+2

History

• 💚 Build #288704 succeeded 0ded2e2
• 💔 Build #288602 failed ed8aff7
• 💔 Build #288263 failed e3b18c3
• 💔 Build #287913 failed 36272b6