Deprecated ClusterService and Using NodeClient to fetch meta data

[penghuo]

Signed-off-by: penghuo penghuo@gmail.com

Check List

• New functionality includes testing.
  • All tests pass, including unit test, integration test and doctest
• New functionality has been documented.
  • New functionality has javadoc added
  • New functionality has user manual doc added
• Commits are signed per the DCO using --signoff

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[codecov-commenter]

Codecov Report

Merging #774 (699f0ac) into 2.1 (808813d) will decrease coverage by 0.00%.
The diff coverage is 100.00%.

@@             Coverage Diff              @@
##                2.1     #774      +/-   ##
============================================
- Coverage     97.71%   97.71%   -0.01%     
  Complexity     2801     2801              
============================================
  Files           270      271       +1     
  Lines          6912     6908       -4     
  Branches        439      438       -1     
============================================
- Hits           6754     6750       -4     
  Misses          157      157              
  Partials          1        1              

Flag	Coverage Δ
sql-engine	97.71% <100.00%> (-0.01%)	⬇️

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Impacted Files	Coverage Δ
...ch/sql/opensearch/client/OpenSearchNodeClient.java	100.00% <100.00%> (ø)
.../opensearch/sql/opensearch/executor/Scheduler.java	100.00% <100.00%> (ø)

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