planner: allow refineArgs for plan cache in some situations (#28944)

[ti-srebot]

cherry-pick #28944 to release-5.2
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/29422

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git push git@github.com:ti-srebot/tidb.git pr/29422:release-5.2-83e559db0a7a

---

What problem does this PR solve?

Issue Number: close #28858

Problem Summary:
If we forbid the refineArgs for plan cache. The string <cmp> int will get an wrong answer. Because when we convert the string to double, it will lose precision.

What is changed and how it works?

1. Allow refineArgs for plan cache in some situations. And forbid some plans to cache.
2. When the plan can not be cached, we need to simplify the constant.

Check List

Tests

• Unit test
• 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

'None'

[ti-chi-bot]

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[ti-chi-bot]

@ti-srebot: This cherry pick PR is for a release branch and has not yet been approved by release team.
Adding the do-not-merge/cherry-pick-not-approved label.

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[ti-srebot]

/run-all-tests

[ti-srebot]

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[VelocityLight]

This pull request is closed because it's related version has closed automatic cherry-picking.
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see:

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