branch-3.1:[fix](fe) Preserve narrowing datetimev2 casts in simplify in predicate (#63343)

[starocean999]

pick #63343

What problem does this PR solve?

SimplifyInPredicate could incorrectly remove narrowing DATETIMEV2 casts inside IN predicates.
For expressions such as CAST(datetimev2(6) AS DATETIMEV2(3)) IN (...), the rewrite could turn the predicate
into a direct comparison on the original DATETIMEV2(6) column, which is not semantics-preserving because the cast
uses precision reduction and rounding. The rule also used a binary-based microsecond alignment check instead of a
decimal scale check, which could incorrectly treat some literals as losslessly convertible.

This change restricts the rewrite to non-narrowing DATETIMEV2 casts and fixes the literal alignment check to use
decimal scale factors. It also adds FE unit tests and a regression case for the reported DATETIMEV2 scenario.

What problem does this PR solve?

Issue Number: close #xxx

Related PR: #xxx

Problem Summary:

Release note

None

Check List (For Author)

• Test

  • Regression test
  • Unit Test
  • Manual test (add detailed scripts or steps below)
  • No need to test or manual test. Explain why:
    • This is a refactor/code format and no logic has been changed.
    • Previous test can cover this change.
    • No code files have been changed.
    • Other reason

• Behavior changed:

  • No.
  • Yes.

• Does this need documentation?

  • No.
  • Yes.

Check List (For Reviewer who merge this PR)

• Confirm the release note
• Confirm test cases
• Confirm document
• Add branch pick label

[hello-stephen]

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1. What problem was fixed (it's best to include specific error reporting information). How it was fixed.
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4. Which code was refactored and why was this part of the code refactored?
5. Which functions were optimized and what is the difference before and after the optimization?

[starocean999]

run buildall