[ML] Creating category validation package

[jgowdyelastic]

Moves the server and client side code which performs analysis on data to see whether it is suitable for categorization.
This is currently only used by the categorization job wizard to display this callout:

However this analysis will be useful for the Log Pattern Analysis feature and so moving the code to a package allows easier sharing between ML and AIOPs plugins.

[jgowdyelastic]

@elasticmachine merge upstream

[elasticmachine]

Pinging @elastic/ml-ui (:ml)

[walterra]

Other plugins we maintain are prefixed with either @kbn/aiops-* or @kbn/ml-*. The ml one is more like a prefix as in ML the team, not ML the code or Kibana plugin. Looking back maybe even the aiops ones should be prefixed with ml. Suggest to also prefix this one like @kbn/ml-category-validator. It makes also search for imports we own easier.

[jgowdyelastic]

Suggest to also prefix this one like @kbn/ml-category-validator.

Good spot. I missed that the package ids were different to the directory name.
Updated the package name in e397708

@kbn/category_validator -> @kbn/ml-category-validator

[walterra]

Code LGTM, just added some minor comments.

Would be good to get the missing comments/any counts down, stats can be output like this:

node scripts/build_api_docs --plugin @kbn/ml-category-validator --stats comments
node scripts/build_api_docs --plugin @kbn/ml-category-validator --stats any

[walterra]

Would be good to have a brief description here.

[jgowdyelastic]

Ah, I missed that. Thanks
Updated in 91de94b

[walterra]

Nit: This file might not be necessary, the index.ts in the root of the package could directly import/export categorizationExamplesProvider.

[jgowdyelastic]

Updated in 91de94b

[kibana-ci]

💛 Build succeeded, but was flaky

• Buildkite Build
• Commit: b672387

Failed CI Steps

• FTR Configs #58

Test Failures

• [job] [logs] FTR Configs #58 / AIOps POST /internal/aiops/explain_log_rate_spikes - groups only with ecommerce should return group only in chunks with streaming without compression with flushFix

Metrics [docs]

Module Count

Fewer modules leads to a faster build time

id	before	after	diff
ml	1761	1764	+3

Async chunks

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

id	before	after	diff
ml	3.4MB	3.4MB	+71.0B

Unknown metric groups

API count

id	before	after	diff
@kbn/ml-category-validator	-	32	+32

History

• 💚 Build #143257 succeeded 2d09b51
• 💚 Build #143067 succeeded 91de94b
• 💚 Build #142966 succeeded 6ccb935
• 💔 Build #142957 failed e397708
• 💚 Build #142896 succeeded 6aadeac
• 💔 Build #142890 failed afe9553

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

cc @jgowdyelastic

[peteharverson]

LGTM. Good job getting those API counts down to 0!

Added a comment on the format of comments to add a description for params for future reference.

[peteharverson]

Adding this for reference - note that these will generate the docs, but there will be no description of what the param is. the syntax to use is e.g.

 @param {string} indexPatternTitle the title of the index pattern for which to obtain examples