Add separate metric for cluster manager service events and metrics

[khushbr]

Related commit in Commons: opensearch-project/performance-analyzer-commons@83cb2d4

Check List

• Backport Labels added.
• New functionality includes testing.
  • All tests pass
• New functionality has been documented.
  • New functionality has javadoc added
• Commits are signed per the DCO using --signoff

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.
For more information on following Developer Certificate of Origin and signing off your commits, please check here.

[codecov]

Codecov Report

Merging #579 (d26ee45) into main (7d6206e) will increase coverage by 0.19%.
The diff coverage is 0.00%.

❗ Current head d26ee45 differs from pull request most recent head a05d61c. Consider uploading reports for the commit a05d61c to get more accurate results

@@             Coverage Diff              @@
##               main     #579      +/-   ##
============================================
+ Coverage     69.02%   69.22%   +0.19%     
- Complexity      370      372       +2     
============================================
  Files            45       45              
  Lines          2696     2697       +1     
  Branches        172      172              
============================================
+ Hits           1861     1867       +6     
+ Misses          731      727       -4     
+ Partials        104      103       -1     

Files	Coverage Δ
...lyzer/collectors/ClusterManagerServiceMetrics.java	62.79% <ø> (ø)
.../collectors/ClusterManagerServiceEventMetrics.java	75.49% <0.00%> (+0.83%)	⬆️

... and 1 file with indirect coverage changes

[opensearch-trigger-bot]

The backport to 1.x failed:

The process '/usr/bin/git' failed with exit code 1

To backport manually, run these commands in your terminal:

# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add .worktrees/backport-1.x 1.x
# Navigate to the new working tree
cd .worktrees/backport-1.x
# Create a new branch
git switch --create backport/backport-579-to-1.x
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 951df934428562f1c0978310c6e3909c03e4aeda
# Push it to GitHub
git push --set-upstream origin backport/backport-579-to-1.x
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-1.x

Then, create a pull request where the base branch is 1.x and the compare/head branch is backport/backport-579-to-1.x.