[feature](fe) Support Paimon DDL and external table properties

[suxiaogang223]

What problem does this PR solve?

Issue Number: None

Related PR: None

Problem Summary:

Doris routes external table column changes to connector metadata operations, but Paimon did not implement those operations. External table property changes were also only handled for auto_analyze_policy, so connector properties were rejected during analysis or silently ignored.

This change implements Paimon column add/drop/rename and table rename operations, routes external table property updates through ExternalCatalog, and adds Paimon and Iceberg property update implementations with metadata cache refresh.

Release note

Support Paimon ALTER TABLE column and table rename operations, and Paimon/Iceberg table property updates.

Check List (For Author)

• Test
  • Regression test
  • Unit Test
  • Manual test
  • No need to test or manual test.
• Behavior changed:
  • No.
  • Yes. Paimon supports ALTER TABLE column/table rename operations, and Paimon/Iceberg external tables support property updates.
• Does this need documentation?
  • No.
  • Yes.

Validation:

• ./run-fe-ut.sh --run org.apache.doris.datasource.paimon.PaimonMetadataOpsTest,org.apache.doris.nereids.trees.plans.commands.info.ModifyTablePropertiesOpTest
• ./build.sh --fe
• git diff --check

The external-environment regression cases were added but not executed locally because they require the Paimon and Iceberg test services.

Check List (For Reviewer who merge this PR)

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

[hello-stephen]

Thank you for your contribution to Apache Doris.
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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?
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