add gzip compression for check_leader requests (#14721)

[ti-chi-bot]

This is an automated cherry-pick of #14721

What is changed and how it works?

Issue Number: Ref #14553

What's Changed:

The size of check_leader requests is related to the number of leaders. Generally, each region will takes 7 bytes in request and 1 byte in response, when the number of leader is high, the compression saves about 60% traffic in my test.

Add gzip compression for check_leader requests.

Related changes

• PR to update pingcap/docs/pingcap/docs-cn:
• Need to cherry-pick to the release branch

Check List

Tests

• Manual test (add detailed scripts or steps below)

• CPU utilization (resolved-ts.advance-ts-interval=100ms, 2000 regions per store)

Before

After

Side effects

• Performance regression
  • Consumes more CPU

Release note

Compress traffic of check_leader requests.

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• ekexium
• overvenus

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[you06]

/cherry-pick-invite

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[you06]

/merge

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

Commit hash: ddd8713