ddl, tests: add expression default values feature relevant tests for some DDLs and fix a related bug

[zimulala]

What problem does this PR solve?

Issue Number: close #51554, close #51570

Problem Summary:

What changed and how does it work?

• Add expression default values feature relevant tests for "modify column", "set/drop default" and "add index"
• When the default value is an expression, changing it to a constant by "set default" can be problematic

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.

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

[tiprow]

Hi @zimulala. Thanks for your PR.

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[codecov]

Codecov Report

Merging #51571 (7de105a) into master (b2c3e67) will increase coverage by 1.4857%.
Report is 49 commits behind head on master.
The diff coverage is 100.0000%.

Additional details and impacted files

@@               Coverage Diff                @@
##             master     #51571        +/-   ##
================================================
+ Coverage   70.7440%   72.2297%   +1.4857%     
================================================
  Files          1464       1471         +7     
  Lines        435644     447615     +11971     
================================================
+ Hits         308192     323311     +15119     
+ Misses       108146     104014      -4132     
- Partials      19306      20290       +984     

Flag	Coverage Δ
integration	48.8458% <100.0000%> (?)
unit	70.5237% <100.0000%> (-0.0191%)	⬇️

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

Components	Coverage Δ
dumpling	53.9957% <ø> (ø)
parser	∅ <ø> (∅)
br	50.5197% <ø> (+4.7065%)	⬆️

[zimulala]

/test check-dev2

[tiprow]

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[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: Defined2014, tangenta

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• OWNERS [Defined2014,tangenta]
• pkg/ddl/OWNERS [tangenta]

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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2024-03-11 02:43:38.000511232 +0000 UTC m=+653445.022757634: ☑️ agreed by Defined2014.
• 2024-03-11 02:46:49.578654849 +0000 UTC m=+653636.600901239: ☑️ agreed by tangenta.

[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-7.1: #52582.

[ti-chi-bot]

In response to a cherrypick label: new pull request could not be created: failed to create pull request against pingcap/tidb#release-7.5 from head ti-chi-bot:cherry-pick-51571-to-release-7.5: the GitHub API request returns a 403 error: {"message":"You have exceeded a secondary rate limit and have been temporarily blocked from content creation. Please retry your request again later. If you reach out to GitHub Support for help, please include the request ID 98EE:21F144:4FFBAF3:80C0803:6639C131 and timestamp 2024-05-07 05:50:41 UTC.","documentation_url":"https://docs.github.com/rest/overview/rate-limits-for-the-rest-api#about-secondary-rate-limits"}

[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-7.5: #53394.