IDM: Migrates kbn_server to a dev-only package

[tylersmalley]

redo of: #145785 due to failures when it hit main resulting in a revert.

fix #145193

Migrates core/server/test-helpers/kbn_server to a package
Updates imports across repo

Checklist

Delete any items that are not applicable to this PR.

• Unit or functional tests were updated or added to match the most common scenarios

[tylersmalley]

I will go ahead and merge this on a green CI ahead of any codeowner reviews, as they were completed on the original PR.

[elasticmachine]

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

[elasticmachine]

Pinging @elastic/fleet (Team:Fleet)

[TinaHeiligers]

LGTM

[kibana-ci]

💚 Build Succeeded

• Buildkite Build
• Commit: 1825dca

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/core-test-helpers-kbn-server	-	46	+46

Any counts in public APIs

Total count of every any typed public API. Target amount is 0. Run node scripts/build_api_docs --plugin [yourplugin] --stats any for more detailed information.

id	before	after	diff
@kbn/core-test-helpers-kbn-server	-	1	+1

Public APIs missing exports

Total count of every type that is part of your API that should be exported but is not. This will cause broken links in the API documentation system. Target amount is 0. Run node scripts/build_api_docs --plugin [yourplugin] --stats exports for more detailed information.

id	before	after	diff
@kbn/config	8	9	+1

Unknown metric groups

API count

id	before	after	diff
@kbn/core-test-helpers-kbn-server	-	52	+52

ESLint disabled in files

id	before	after	diff
osquery	1	2	+1

ESLint disabled line counts

id	before	after	diff
enterpriseSearch	19	21	+2
fleet	59	65	+6
osquery	109	115	+6
securitySolution	443	449	+6
total			+20

Total ESLint disabled count

id	before	after	diff
enterpriseSearch	20	22	+2
fleet	68	74	+6
osquery	110	117	+7
securitySolution	520	526	+6
total			+21

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@elasticmachine merge upstream