[PoC] Discover controls customization

[davismcphee]

Summary

PoC implementation of controls in Discover using the customization framework.

Checklist

• 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

[kibana-ci]

💔 Build Failed

• Buildkite Build
• Commit: ac58415
• Interpreting CI Failures

Failed CI Steps

• Build API Docs
• Jest Tests #9
• Check Types

Test Failures

• [job] [logs] Jest Tests #9 / test fetchAll changes of fetchStatus when starting with FetchStatus.UNINITIALIZED
• [job] [logs] Jest Tests #9 / test fetchAll emits loading and documents on documents$ correctly
• [job] [logs] Jest Tests #9 / test fetchAll emits loading and hit count on totalHits$ correctly
• [job] [logs] Jest Tests #9 / test fetchAll should not set COMPLETE if an ERROR has been set on main$
• [job] [logs] Jest Tests #9 / test fetchAll should only fail totalHits$ query not main$ for error from that query
• [job] [logs] Jest Tests #9 / test fetchAll should use charts query to fetch total hit count when chart is visible
• [job] [logs] Jest Tests #9 / updateVolatileSearchSource does not explicitly request fieldsFromSource when not using fields API
• [job] [logs] Jest Tests #9 / updateVolatileSearchSource updates a given search source
• [job] [logs] Jest Tests #9 / updateVolatileSearchSource updates a given search source when showUnmappedFields option is set to true
• [job] [logs] Jest Tests #9 / updateVolatileSearchSource updates a given search source with the usage of the new fields api

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
discover	423.0KB	423.4KB	+423.0B
unifiedSearch	212.4KB	212.4KB	+46.0B
total			+469.0B

Page load bundle

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

id	before	after	diff
unifiedSearch	34.0KB	34.0KB	+36.0B

History

• 💔 Build #133738 failed 0ba117172bbdc08695d61c8926151319fc3a37ad

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

cc @davismcphee

[kertal]

Not needed anymore