planner: check for decimal format in cast expr (#20836)

[ti-srebot]

cherry-pick #20836 to release-3.0

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What problem does this PR solve?

Issue Number: close #20295

Problem Summary: There's no check for decimal format in cast expressions in TiDB.

select cast( (select sum(a) from t1) as decimal(65,65));
select CONVERT( 2, DECIMAL(62,60) ) ;
select CONVERT( 2, DECIMAL(66,29) ) ;

What is changed and how it works?

• Check for decimal format in cast expressions during Preprocess.

Related changes

• Need to cherry-pick to the release branch

Check List

Tests

• Unit test

Side effects

• Performance regression
  • Consumes more CPU
  • Consumes more MEM
• Breaking backward compatibility

Release note

• Add checks for decimal format in cast expressions.

[ti-srebot]

/run-all-tests

[ti-srebot]

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

[dyzsr]

/run-all-tests

[lzmhhh123]

LGTM

[dyzsr]

/run-all-tests

[qw4990]

/run-all-tests

[zz-jason]

close due to outdated, for now, we only cherry-pick critical bug-fixes to release-3.0