Add ClusterStateRequest parameter to cluster state transport request

[dbwiddis]

Companion PR on OpenSearch: opensearch-project/OpenSearch#7066

Description

Adds the ability to send a ClusterStateRequest parameter when requesting Cluster State, to limit the values returned (and reduce transport bandwidth). To get the old behavior, use new ClusterStateRequest().all() as the parameter.

Issues Resolved

Fixes #354 (caveat: we should decide whether to add a call to this method in the SDKClient (which requires passing the TransportService around). For now it is accessible to extensions via ExtensionsRunner.getSdkTransportService().

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[codecov-commenter]

Codecov Report

Merging #668 (cf3943a) into main (94618e0) will increase coverage by 2.57%.
The diff coverage is 63.63%.

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@@             Coverage Diff              @@
##               main     #668      +/-   ##
============================================
+ Coverage     64.17%   66.75%   +2.57%     
- Complexity      274      281       +7     
============================================
  Files            55       55              
  Lines          1164     1164              
  Branches         38       38              
============================================
+ Hits            747      777      +30     
+ Misses          404      374      -30     
  Partials         13       13              

Impacted Files	Coverage Δ
...main/java/org/opensearch/sdk/ExtensionsRunner.java	78.64% <ø> (+1.41%)	⬆️
...arch/sdk/handlers/ClusterStateResponseHandler.java	52.94% <ø> (+17.64%)	⬆️
...n/java/org/opensearch/sdk/SDKTransportService.java	78.84% <60.00%> (+31.22%)	⬆️
...ain/java/org/opensearch/sdk/SDKClusterService.java	100.00% <100.00%> (ø)

... and 1 file with indirect coverage changes

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[saratvemulapalli]

This will conflict with #647. We'll probably get your changes in and I'll rebase.

[dbwiddis]

Yeah, I thought so.

Also, I'll be doing another PR for GetFieldMappings which will follow this template, and we (you) may want to make a more generic protobuf action for all the TransportActions (with associated ActionRequest/ActionResponse) with similar casing to this... they all implement Writeable.

Or we could adapt the ProxyAction code to do this. I started down that road but it got pretty spaghetti pretty fast.

[dbwiddis]

Based on feedback about sending cluster state over transport, I'm closing this PR in favor of targeted API requests for the information we need.