client: split the meta storage client

[JmPotato]

What problem does this PR solve?

Issue Number: ref #8690.

What is changed and how does it work?

Split the meta storage client from the client definitions.

Check List

Tests

• Unit test
• Integration test

Release note

None.

[JmPotato]

/cc @okJiang @rleungx @lhy1024

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[codecov]

Codecov Report

Attention: Patch coverage is 78.94737% with 8 lines in your changes missing coverage. Please review.

Project coverage is 75.23%. Comparing base (40fe83e) to head (dac21a6).
Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #8822      +/-   ##
==========================================
- Coverage   75.26%   75.23%   -0.04%     
==========================================
  Files         456      456              
  Lines       71608    71608              
==========================================
- Hits        53898    53875      -23     
- Misses      14281    14305      +24     
+ Partials     3429     3428       -1     

Flag	Coverage Δ
unittests	75.23% <78.94%> (-0.04%)	⬇️

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[rleungx]

Do we need clients layer?

[JmPotato]

Later I will move the TSO client into this layer too.

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: lhy1024, rleungx

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• OWNERS [lhy1024,rleungx]

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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2024-11-19 02:30:20.905821249 +0000 UTC m=+928183.096690241: ☑️ agreed by lhy1024.
• 2024-11-19 06:33:18.263403875 +0000 UTC m=+942760.454272877: ☑️ agreed by rleungx.