[API DOCS] Telemetry

[afharo]

Summary

Resolves #98516: This PR cleans up all the unused APIs exposed by the telemetry plugin and documents the exposed ones.

When running node scripts/build_api_docs --plugin telemetry --stats any --stats comments --stats exports we still get the following warnings.

 info --- Plugin 'telemetry' ----`
 info 0 API items with ANY
┌─────────┐
│ (index) │
├─────────┤
└─────────┘
 info 4 API items missing comments
┌─────────┬─────────────────────────────────┬────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┐
│ (index) │               id                │                                                            link                                                            │
├─────────┼─────────────────────────────────┼────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┤
│    0    │ 'def-server.getClusterUuids.$1' │ 'https://github.com/elastic/kibana/tree/master/src/plugins/telemetry/server/telemetry_collection/get_cluster_stats.ts#L26' │
│    1    │  'def-server.getLocalStats.$1'  │  'https://github.com/elastic/kibana/tree/master/src/plugins/telemetry/server/telemetry_collection/get_local_stats.ts#L63'  │
│    2    │  'def-server.getLocalStats.$2'  │  'https://github.com/elastic/kibana/tree/master/src/plugins/telemetry/server/telemetry_collection/get_local_stats.ts#L64'  │
│    3    │  'def-server.getLocalStats.$3'  │  'https://github.com/elastic/kibana/tree/master/src/plugins/telemetry/server/telemetry_collection/get_local_stats.ts#L65'  │
└─────────┴─────────────────────────────────┴────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┘

This is because the current tool is not able to link the JSDocs and the methods declared as const myFn = ({ destructVar }) => arrowFnResult. However, hopefully, when we complete #93185, we'll be able to stop exposing those APIs.

UPDATE: Setting @internal to those APIs solves the issue. Since they are only used internally by the X-Pack Telemetry extension, I think that's a good enough approach in this case 👍. Running the same command again, we get:

 info --- Plugin 'telemetry'  passes all checks ----

Checklist

• Documentation was added for features that require explanation or tutorials

For maintainers

• This was checked for breaking API changes and was labeled appropriately

[elasticmachine]

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

[elasticmachine]

Pinging @elastic/kibana-telemetry (Team:KibanaTelemetry)

[Bamieh]

I'm sure that was me with this faulty mac keyboard 😓

[afharo]

Or me 😅 I have a spellchecker in my IDE because I'm always mixing up keystrokes... In mind, I think that I know what I'm doing, but my fingers think otherwise... 🤦

[Bamieh]

LGTM :elasticheart:

[kibanamachine]

💚 Build Succeeded

• continuous-integration/kibana-ci/pull-request
• Commit: 5b0472a
• Storybooks Preview

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
telemetry	78	0	-78

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
telemetry	1	0	-1

Page load bundle

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

id	before	after	diff
telemetry	35.9KB	36.4KB	+495.0B

Unknown metric groups

API count

id	before	after	diff
telemetry	83	40	-43

History

• 💚 Build #123060 succeeded 9c4e7996ef3e5627d1dd1f25f6ec6c58860cbcaa
• 💚 Build #122964 succeeded acc2b721e1ca8dfacc2649c5da8073c15781f313

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

[kibanamachine]

💚 Backport successful

Status	Branch	Result
✅	7.x

This backport PR will be merged automatically after passing CI.