*: unify the use of PD API URL constants

[JmPotato]

What problem does this PR solve?

Issue Number: ref #35319.

What is changed and how it works?

Unify the use of PD API URL constants to make sure it can be maintained more easily.

Check List

Tests

• Unit test
• Integration test

Release note

None

[JmPotato]

/cc @hawkingrei @nolouch

[hawkingrei]

Great job.

It is a better way to supply a pd client library for tidb.

[CabinfeverB]

Great job.

It is a better way to supply a pd client library for tidb.

a HTTP client?

[codecov]

Codecov Report

Merging #48132 (171e66d) into master (cc12200) will increase coverage by 1.3900%.
Report is 19 commits behind head on master.
The diff coverage is 50.6849%.

Additional details and impacted files

@@               Coverage Diff                @@
##             master     #48132        +/-   ##
================================================
+ Coverage   71.5920%   72.9821%   +1.3900%     
================================================
  Files          1400       1424        +24     
  Lines        405894     414456      +8562     
================================================
+ Hits         290588     302479     +11891     
+ Misses        95488      93106      -2382     
+ Partials      19818      18871       -947     

Flag	Coverage Δ
integration	42.6871% <0.0000%> (?)
unit	71.7848% <50.6849%> (+0.1927%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Components	Coverage Δ
dumpling	55.5260% <ø> (+1.4757%)	⬆️
parser	∅ <ø> (∅)
br	49.2385% <48.2758%> (-3.6594%)	⬇️

[hawkingrei]

Great job.
It is a better way to supply a pd client library for tidb.

a HTTP client?

Yes, but it is enough for this pr.

[JmPotato]

/retest-required

[JmPotato]

/test check-dev2

[tiprow]

@JmPotato: The specified target(s) for /test were not found.
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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2023-10-31 06:54:38.558671493 +0000 UTC m=+2936076.145781638: ☑️ agreed by hawkingrei.
• 2023-10-31 08:00:33.241524479 +0000 UTC m=+2940030.828634625: ☑️ agreed by nolouch.

[JmPotato]

@lance6716 @Leavrth Please help take a look, thx.

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: CabinfeverB, hawkingrei, lance6716, Leavrth, nolouch

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Needs approval from an approver in each of these files:

• OWNERS [Leavrth,hawkingrei,lance6716]
• br/OWNERS [Leavrth]
• br/pkg/lightning/OWNERS [lance6716]
• pkg/domain/OWNERS [lance6716]

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[JmPotato]

/test mysql-test

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@JmPotato: The specified target(s) for /test were not found.
The following commands are available to trigger required jobs:

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Use /test all to run all jobs.

In response to this:

/test mysql-test

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[JmPotato]

/test mysql-test

[tiprow]

@JmPotato: The specified target(s) for /test were not found.
The following commands are available to trigger required jobs:

• /test tiprow_fast_test

Use /test all to run all jobs.

In response to this:

/test mysql-test

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[JmPotato]

/test mysql-test

[tiprow]

@JmPotato: The specified target(s) for /test were not found.
The following commands are available to trigger required jobs:

• /test tiprow_fast_test

Use /test all to run all jobs.

In response to this:

/test mysql-test

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.