ddl: fix the primary key in index is not in restored format (#53118)

[ti-chi-bot]

This is an automated cherry-pick of #53118

What problem does this PR solve?

Issue Number: close #52510

Problem Summary:
when fast reorg and new collation are enabled, index backfilling only considers the need to restore the index columns, but ignores the primary key columns. The result is that the primary key in the index is not restored.

What changed and how does it work?

When considering the need to restore an index, check both the index columns and the primary key columns.

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.

- Fix the collation of the primary key in secondary indexes is wrong when tidb_ddl_enable_fast_reorg is enabled

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

❗ No coverage uploaded for pull request base (release-8.1@64ca76e). Click here to learn what that means.

Additional details and impacted files

@@               Coverage Diff                @@
##             release-8.1     #53132   +/-   ##
================================================
  Coverage               ?   71.2073%           
================================================
  Files                  ?       1463           
  Lines                  ?     421048           
  Branches               ?          0           
================================================
  Hits                   ?     299817           
  Misses                 ?     100781           
  Partials               ?      20450           

Flag	Coverage Δ
unit	71.2073% <100.0000%> (?)

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

Components	Coverage Δ
dumpling	53.9957% <0.0000%> (?)
parser	∅ <0.0000%> (?)
br	40.9887% <0.0000%> (?)

[djshow832]

/retest

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

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

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

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

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2024-05-09 08:39:27.971396437 +0000 UTC m=+1124121.728532010: ☑️ agreed by tangenta.
• 2024-05-10 02:38:08.802662612 +0000 UTC m=+1188842.559798182: ☑️ agreed by YangKeao.