client/http, api/middleware: enhance the retry logic of the HTTP client

[JmPotato]

What problem does this PR solve?

Issue Number: ref #7300, #8142.

What is changed and how does it work?

Schedule a member change check when the HTTP status code is 503 or receives a leader/primary change error.

Check List

Tests

• Unit test
• Integration test

Release note

None.

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• HuSharp
• rleungx

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[codecov]

Codecov Report

Attention: Patch coverage is 82.69231% with 9 lines in your changes are missing coverage. Please review.

Project coverage is 77.29%. Comparing base (199b017) to head (1794635).

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #8229      +/-   ##
==========================================
+ Coverage   77.26%   77.29%   +0.03%     
==========================================
  Files         471      471              
  Lines       61346    61369      +23     
==========================================
+ Hits        47401    47438      +37     
+ Misses      10383    10373      -10     
+ Partials     3562     3558       -4     

Flag	Coverage Δ
unittests	77.29% <82.69%> (+0.03%)	⬆️

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[HuSharp]

/merge

[ti-chi-bot]

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[ti-chi-bot]

This pull request has been accepted and is ready to merge.

Commit hash: 1794635

[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-8.1: #8464.