topsql, pprof: use hex string but not binary sql/plan digest in goroutine label (#52216)

[ti-chi-bot]

This is an automated cherry-pick of #52216

What problem does this PR solve?

Issue Number: close #52215

Problem Summary:

Use the hex string in goroutine labels. It'll allow us to use the go tool pprof and graphviz to handle the protobuf.

Before this PR returned, you can workaround by generating a dot file, and use iconv to handle the non-utf8 characters manually.

What changed and how does it work?

Use the pre-ecoded hex string, rather than bytes.

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
• No need to test

  • I checked and no code files have been changed.

Run any tests (which runs at least some SQLs) and profile it with -cpuprofile, and you'll find the protobuf is useable now.

Release note

None

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (release-7.5@fde2234). Click here to learn what that means.
The diff coverage is 81.4814%.

Additional details and impacted files

@@               Coverage Diff                @@
##             release-7.5     #52324   +/-   ##
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  Coverage               ?   71.9779%           
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  Files                  ?       1410           
  Lines                  ?     409406           
  Branches               ?          0           
================================================
  Hits                   ?     294682           
  Misses                 ?      94892           
  Partials               ?      19832           

Flag	Coverage Δ
unit	71.9779% <81.4814%> (?)

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

Components	Coverage Δ
dumpling	53.9913% <0.0000%> (?)
parser	∅ <0.0000%> (?)
br	53.3131% <0.0000%> (?)

[YangKeao]

LGTM

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: hawkingrei, YangKeao

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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2024-04-03 05:03:50.047027941 +0000 UTC m=+420291.574568486: ☑️ agreed by hawkingrei.
• 2024-04-03 06:12:01.842308586 +0000 UTC m=+424383.369849133: ☑️ agreed by YangKeao.