[rule based autotagging] Add Create Rule API Logic

[ruai0511]

Description

This PR introduces the create Rule API Logic.

An exampe API request is:

curl -XPUT "localhost:9200/_rules/workload_group"  -H 'Content-Type: application/json' -d '     
{
    "description": "description",
     "index_pattern": ["log*", "event*"],
     "workload_group": "EITBzjFkQ6CA-semNWGtRQ"
}'

And the return would be

{
   "_id":"Kqqra5YBzZOW_5Q0ALDc",
   "description":"description",
   "index_pattern":["log*", "event*"],
   "workload_group":"EITBzjFkQ6CA-semNWGtRQ",
   "updated_at":"2025-04-25T06:38:10.787Z"
}

Rule Schema PR:
#17238
RFC:
#16797

Check List

• Functionality includes testing.
• API changes companion pull request created, if applicable.
• Public documentation issue/PR created, if applicable.

[github-actions]

❌ Gradle check result for 90e2b4c: FAILURE

Please examine the workflow log, locate, and copy-paste the failure(s) below, then iterate to green. Is the failure a flaky test unrelated to your change?

[github-actions]

❌ Gradle check result for 85ea24e: FAILURE

Please examine the workflow log, locate, and copy-paste the failure(s) below, then iterate to green. Is the failure a flaky test unrelated to your change?

[github-actions]

❌ Gradle check result for e215963: FAILURE

Please examine the workflow log, locate, and copy-paste the failure(s) below, then iterate to green. Is the failure a flaky test unrelated to your change?

[github-actions]

✅ Gradle check result for 778645c: SUCCESS

[jainankitk]

LGTM!

[opensearch-trigger-bot]

The backport to 2.x failed:

The process '/usr/bin/git' failed with exit code 128

To backport manually, run these commands in your terminal:

# Navigate to the root of your repository
cd $(git rev-parse --show-toplevel)
# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add ../.worktrees/OpenSearch/backport-2.x 2.x
# Navigate to the new working tree
pushd ../.worktrees/OpenSearch/backport-2.x
# Create a new branch
git switch --create backport/backport-17792-to-2.x
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 4d6f8bafe489bde867b783c6facd189657ec34e6
# Push it to GitHub
git push --set-upstream origin backport/backport-17792-to-2.x
# Go back to the original working tree
popd
# Delete the working tree
git worktree remove ../.worktrees/OpenSearch/backport-2.x

Then, create a pull request where the base branch is 2.x and the compare/head branch is backport/backport-17792-to-2.x.

[jainankitk]

Removed the stale backport 2.x label!