executor,store/copr: fix index merge, distsql request's key ranges should be sorted (#36633)

[ti-srebot]

cherry-pick #36633 to release-6.2
You can switch your code base to this Pull Request by using git-extras:

# In tidb repo:
git pr https://github.com/pingcap/tidb/pull/36704

After apply modifications, you can push your change to this PR via:

git push [email protected]:ti-srebot/tidb.git pr/36704:release-6.2-8b919bf8930e

---

What problem does this PR solve?

Issue Number: close #36632

Problem Summary:

What is changed and how it works?

The key range for distsql request should be sorted!
Because locate region for the key ranges use a binary search pattern.

Check List

Tests

• Unit test
• Integration test

This bug is found by our integration test.

• Manual test (add detailed scripts or steps below)
• No code

Side effects

• Performance regression: Consumes more CPU
• Performance regression: Consumes more Memory
• Breaking backward compatibility

Documentation

• Affects user behaviors
• Contains syntax changes
• Contains variable changes
• Contains experimental features
• Changes MySQL compatibility

Release note

Please refer to Release Notes Language Style Guide to write a quality release note.

None

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• XuHuaiyu
• wshwsh12

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[ti-srebot]

/run-all-tests

[ti-srebot]

@tiancaiamao you're already a collaborator in bot's repo.

[lcwangchao]

/merge

[ti-chi-bot]

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

Commit hash: 5d3f776

[sre-bot]

Code Coverage Details: https://codecov.io/github/pingcap/tidb/commit/5d3f776493efbb50dea2e5704f8f997e33c7accb