Load: Optimized the downgraded logic for tsFile to insert more data when tsFile corrupted

[Caideyipi]

Description

As the title said.

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This PR has:

• been self-reviewed.
  • concurrent read
  • concurrent write
  • concurrent read and write
• added documentation for new or modified features or behaviors.
• added Javadocs for most classes and all non-trivial methods.
• added or updated version, license, or notice information
• added comments explaining the "why" and the intent of the code wherever would not be obvious
  for an unfamiliar reader.
• added unit tests or modified existing tests to cover new code paths, ensuring the threshold
  for code coverage.
• added integration tests.
• been tested in a test IoTDB cluster.

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Key changed/added classes (or packages if there are too many classes) in this PR

[sonarqubecloud]

Quality Gate failed

Failed conditions
C Reliability Rating on New Code (required ≥ A)

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[luoluoyuyu]

Review summary

Introduces LoadTreeTsFileTabletIterator and uses it in LoadTreeStatementDataTypeConvertExecutionVisitor so corrupted TsFiles can yield more insertable tablets on downgrade. Adds unit tests for the converter path.

Please fix failing datanode unit tests before merge.

[luoluoyuyu]

Replacing TsFileInsertionEventScanParser with LoadTreeTsFileTabletIterator centralizes corrupted-file handling for load. Please document what data may still be skipped versus inserted when a file is partially corrupted.