Added transport action for bulk async shard fetch for primary shards.

[sudarshan-baliga]

Description

This PR for adding the transport action for the async fetching of the shard information for bulk of shards from the nodes in a single request per node. Code is inspired by the existing transport action TransportNodesListGatewayStartedShards.java which fetches just one shard information from the node per request.

• Added transport action TransportNodesBulkListGatewayStartedShards.java for fetching the shards data on a node in bulk.
• Added helper class TransportNodesGatewayStartedShardHelper.java for reducing the code duplication in new transport class TransportNodesBulkListGatewayStartedShards.java and existing transport class TransportNodesListGatewayStartedShards.java.
• POC code where testing was done https://github.com/opensearch-project/OpenSearch/pull/7269/files#diff-c1a7825492dba9f1ba34affffcead20eab136eb67283f89d81295fcef2a8a3ff

Related Issues

Resolves #[Issue number to be closed when this PR is merged]

• [BUG] Async shard fetches taking up GBs of memory causing ClusterManager JVM to spike with large no. of shards (> 50k) #5098

Check List

• [ Y] New functionality includes testing.
  • [ Y] All tests pass
• [Y ] New functionality has been documented.
  • [Y ] New functionality has javadoc added
• [Y ] Commits are signed per the DCO using --signoff
• [ Y] Commit changes are listed out in CHANGELOG.md file (See: Changelog)

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.

[github-actions]

Gradle Check (Jenkins) Run Completed with:

• RESULT: FAILURE ❌
• URL: https://build.ci.opensearch.org/job/gradle-check/18157/
• CommitID: aedcf25
  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?