Heatmap small multiples

[stratoula]

Summary

Enables split chart in agg based heatmaps (small multiples) and makes the EC implementation the default. It also marks the advanced setting that changes the implementation as deprecated.

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

[stratoula]

ℹ️ I am testing the x labels here instead of the y labels as there is this bug on std deviation #154523

[elasticmachine]

Pinging @elastic/kibana-visualizations @elastic/kibana-visualizations-external (Team:Visualizations)

[ThomThomson]

Presentation team functional test changes LGTM! Code only review

[nickofthyme]

Still reviewing code and testing it out locally but have a few comments in the meantime.

[nickofthyme]

Tested again locally and all looks good to me! 🎉

[kibana-ci]

💛 Build succeeded, but was flaky

• Buildkite Build
• Commit: fd0e9e6

Failed CI Steps

• FTR Configs #39

Metrics [docs]

Module Count

Fewer modules leads to a faster build time

id	before	after	diff
expressionHeatmap	118	120	+2
visTypeHeatmap	19	18	-1
total			+1

Async chunks

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

id	before	after	diff
expressionHeatmap	89.2KB	90.6KB	+1.3KB
visualizations	259.9KB	259.5KB	-435.0B
total			+934.0B

Page load bundle

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

id	before	after	diff
visTypeHeatmap	12.5KB	12.2KB	-345.0B

Unknown metric groups

ESLint disabled line counts

id	before	after	diff
securitySolution	394	397	+3

Total ESLint disabled count

id	before	after	diff
securitySolution	474	477	+3

History

• 💚 Build #120523 succeeded 5c1f724
• 💚 Build #119645 succeeded c1f386a
• 💚 Build #118644 succeeded 2721970
• 💔 Build #118626 failed cf9a079
• 💔 Build #118591 failed 8002ceb
• 💔 Build #118588 failed b7c7552

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