[fix](datetime) preserve date/time v1 compatibility during rolling upgrade

[jacktengg]

Old FE plans can carry DATE, DATETIME, and legacy TIME types, while the new BE implementations default to V2 physical columns. This may produce a logical/physical type mismatch and crash downstream casts during a rolling upgrade.

Dispatch now, curdate, utc_timestamp, makedate, and convert_tz according to the plan types. Normalize the removed thrift TIME value to TIMEV2, reject unsupported result types explicitly, and cover the legacy plan paths in unit tests.

What problem does this PR solve?

Issue Number: close #xxx

Related PR: #xxx

Problem Summary:

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• Test

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  • Unit Test
  • Manual test (add detailed scripts or steps below)
  • No need to test or manual test. Explain why:
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• Behavior changed:

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• Does this need documentation?

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  • Yes.

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[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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[jacktengg]

run buildall