[8.x] feat(rca): display investigations stats (#193069)

[kibanamachine]

Backport

This will backport the following commits from main to 8.x:

• feat(rca): display investigations stats (#193069)

Questions ?

Please refer to the Backport tool documentation

[kibana-ci]

💛 Build succeeded, but was flaky

• Buildkite Build
• Commit: 9a100af

Failed CI Steps

• FTR Configs #27

Test Failures

• [job] [logs] FTR Configs #27 / dashboard app - group 4 dashboard empty state adds a new data view when no data views

Metrics [docs]

Module Count

Fewer modules leads to a faster build time

id	before	after	diff
investigateApp	554	557	+3

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/investigation-shared	62	66	+4

Async chunks

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

id	before	after	diff
investigateApp	460.6KB	463.3KB	+2.7KB

Page load bundle

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

id	before	after	diff
investigateApp	12.9KB	13.0KB	+58.0B

Unknown metric groups

API count

id	before	after	diff
@kbn/investigation-shared	62	66	+4

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

cc @kdelemme