[fix](fe) Use updated Routine Load CSV parser properties

[0AyanamiRei]

What problem does this PR solve?

Issue Number: None

Related PR: None

Problem Summary: RoutineLoadJob kept CSV enclose and escape values in both persisted jobProperties and separate in-memory byte fields. ALTER ROUTINE LOAD updated only jobProperties, while newly planned Kafka and Kinesis tasks used the stale fields from CREATE ROUTINE LOAD.

This change makes persisted jobProperties the single job-level source of truth. RoutineLoadJob derives the parser bytes through its getters, and each new task receives a snapshot of the current values. ALTER execution, journal replay, and checkpoint loading already preserve jobProperties, so no load-description replay or checkpoint-specific repair is needed.

Release note

ALTER ROUTINE LOAD now applies updated CSV enclose and escape characters to subsequent tasks.

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

Unit test executed:

DORIS_THIRDPARTY=/path/to/thirdparty-with-thrift-0.24.0 ./run-fe-ut.sh --run org.apache.doris.load.routineload.KafkaRoutineLoadJobTest

Result: 12 tests passed.

The Kafka regression test truncates the table after ALTER and publishes a row that requires the new enclose and escape values while preserving the existing deterministic expected output. It was not run locally because the configured Kafka regression service is unavailable; CI will run it in the Kafka-enabled environment.

• Behavior changed:

  • No.
  • Yes. New Routine Load tasks use CSV parser properties changed by ALTER.

• 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

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1. What problem was fixed (it's best to include specific error reporting information). How it was fixed.
2. Which behaviors were modified. What was the previous behavior, what is it now, why was it modified, and what possible impacts might there be.
3. What features were added. Why was this function added?
4. Which code was refactored and why was this part of the code refactored?
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