[Backport 2.x] Deprecate and Rename abstract methods from 'Master' terminology to 'ClusterManager'.

[opensearch-trigger-bot]

Backport 2a1b239 from #4032

This PR deprecates and renames the following abstract methods:

In class TransportMasterNodeAction -
abstract void masterOperation(Request request, ClusterState state, ActionListener listener)

In class TransportClusterInfoAction -
abstract void doMasterOperation(Request request, String[] concreteIndices, ClusterState state, ActionListener listener)

In class TestCluster:
public abstract int numDataAndMasterNodes();

and the following concrete methods:

In class TransportMasterNodeAction -
void masterOperation(Task task, Request request, ClusterState state, ActionListener<Response> listener)

In class TransportClusterInfoAction -
void masterOperation(final Request request, final ClusterState state, final ActionListener<Response> listener)

[github-actions]

Gradle Check (Jenkins) Run Completed with:

• RESULT: SUCCESS ✅
• URL: https://build.ci.opensearch.org/job/gradle-check/1125/
• CommitID: 5b01a97

[codecov-commenter]

Codecov Report

Merging #4048 (5b01a97) into 2.x (053cf55) will increase coverage by 0.06%.
The diff coverage is 20.00%.

@@             Coverage Diff              @@
##                2.x    #4048      +/-   ##
============================================
+ Coverage     70.49%   70.56%   +0.06%     
- Complexity    56511    56542      +31     
============================================
  Files          4532     4532              
  Lines        272114   272126      +12     
  Branches      40000    40000              
============================================
+ Hits         191832   192015     +183     
+ Misses        64204    63989     -215     
- Partials      16078    16122      +44     

Impacted Files	Coverage Δ
...ation/TransportClusterAllocationExplainAction.java	52.77% <ø> (-6.95%)	⬇️
...tion/TransportAddVotingConfigExclusionsAction.java	83.33% <ø> (-4.17%)	⬇️
...on/TransportClearVotingConfigExclusionsAction.java	83.72% <ø> (-4.66%)	⬇️
...n/cluster/health/TransportClusterHealthAction.java	47.75% <ø> (ø)
...ries/cleanup/TransportCleanupRepositoryAction.java	56.86% <ø> (ø)
...tories/delete/TransportDeleteRepositoryAction.java	100.00% <ø> (ø)
...positories/get/TransportGetRepositoriesAction.java	9.37% <ø> (ø)
...repositories/put/TransportPutRepositoryAction.java	100.00% <ø> (ø)
...tories/verify/TransportVerifyRepositoryAction.java	33.33% <ø> (ø)
...cluster/reroute/TransportClusterRerouteAction.java	44.00% <ø> (+1.33%)	⬆️
... and 529 more

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