tools: support changing service-middleware config through pd-ctl

[rleungx]

What problem does this PR solve?

Issue Number: Close #4373, ref #5739

What is changed and how does it work?

show

config show service-middleware

set

config set service-middleware audit enable-audit false
config set service-middleware rate-limit GetRegion qps 100
config set service-middleware grpc-rate-limit GetRegion qps 100
config set service-middleware rate-limit GetRegion concurrency 10
config set service-middleware grpc-rate-limit GetRegion concurrency 10

detele

config set service-middleware rate-limit GetRegion qps 0
config set service-middleware grpc-rate-limit GetRegion qps 0
config set service-middleware rate-limit GetRegion concurrency 0
config set service-middleware grpc-rate-limit GetRegion concurrency 0

This PR supports using pd-ctl to manage the service middleware config.

Check List

Tests

• Unit test

Release note

None.

[codecov]

Codecov Report

Attention: Patch coverage is 88.00000% with 6 lines in your changes missing coverage. Please review.

Project coverage is 77.57%. Comparing base (642f0e9) to head (f30b042).
Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #8645      +/-   ##
==========================================
+ Coverage   77.50%   77.57%   +0.06%     
==========================================
  Files         474      474              
  Lines       62311    62361      +50     
==========================================
+ Hits        48297    48377      +80     
+ Misses      10448    10417      -31     
- Partials     3566     3567       +1     

Flag	Coverage Δ
unittests	77.57% <88.00%> (+0.06%)	⬆️

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[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

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

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• OWNERS [lhy1024,nolouch]

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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2024-09-23 12:35:13.460249804 +0000 UTC m=+1482983.200673742: ☑️ agreed by lhy1024.
• 2024-09-26 02:39:11.050612668 +0000 UTC m=+1706420.791036621: ☑️ agreed by nolouch.