[Index Management] Add enrich policies fetch api and expose in plugin api

[sabarasaba]

Related to #163159

Summary

In order to unblock the esql team working on the kibana implementation, I'll first merge the API changes for listing enrich policies and a client side public api interface for exposing this mechanism so that the consumer plugins can use it.

Consumers of this plugin can use public apiService from index management by first adding the indexManagement plugin as a dependency of their plugin and then proceding to invoke the method as:

const { data, error } = await indexManagement?.apiService.getAllEnrichPolicies();

Which will then return a serialized list of enriched policies that look something like:

[
    {
      "name": "my-policy",
      "type": "match",
      "sourceIndices": ["users"],
      "matchField": "email",
      "enrichFields": ["first_name", "last_name", "city"]
    },
  ]

How to test

1. Start elasticsearch with yarn es snapshot --license=trial and serverless search solution with yarn start
2. Open the ILM/public/plugin.ts file in your text editor and add indexManagement?.apiService.getAllEnrichPolicies();
3. Go to console and create a test enrich policy
4. Open ILM policies page and make sure that a request for fetching enrich policies has been fired

Create a policy

PUT /users
{
  "mappings": {
    "properties": {
      "email": {
        "type": "keyword"
      },
      "first_name": {
        "type": "text"
      },
      "last_name": {
        "type": "text"
      },
      "city": {
        "type": "text"
      },
      "zip": {
        "type": "keyword"
      },
      "state": {
        "type": "keyword"
      }
    }
  }
}


PUT /_enrich/policy/my-policy
{
  "match": {
    "indices": "users",
    "match_field": "email",
    "enrich_fields": ["first_name", "last_name", "city", "zip", "state"]
  }
}

[elasticmachine]

Pinging @elastic/platform-deployment-management (Team:Deployment Management)

[yuliacech]

Great job, @sabarasaba! 🚀
Tested locally and the api service works as expected. I left a couple of comments in the code, please let me know what you think.
Other than that, I think we should also add some api integration tests for the new route to this folder, but this could also be done in a separate PR.

[sabarasaba]

@elasticmachine merge upstream

[sabarasaba]

Thanks for the review @yuliacech! I've addressed your comments with a4e984e. In regards of the API integration tests I'll aim to have all of them together in a later iteration to avoid bloating in the PRs. I've created an issue for that and also integrated that into the project plan: #163807

[yuliacech]

Latest changes LGTM! Thanks a lot for addressing my comments 👍

[kibana-ci]

💚 Build Succeeded

• Buildkite Build
• Commit: 793dd34

Metrics [docs]

Module Count

Fewer modules leads to a faster build time

id	before	after	diff
indexManagement	491	493	+2

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
indexManagement	172	180	+8

Async chunks

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

id	before	after	diff
indexManagement	523.6KB	522.0KB	-1.6KB

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
indexManagement	3	4	+1

Page load bundle

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

id	before	after	diff
indexManagement	27.9KB	32.4KB	+4.5KB

Unknown metric groups

API count

id	before	after	diff
indexManagement	177	185	+8

History

• 💚 Build #149172 succeeded 379011c
• 💚 Build #149131 succeeded 62be03e
• 💚 Build #149066 succeeded 7895716

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

cc @sabarasaba