Support array-valued schema options in Python

[bvolpato]

Fixes #39557.

Summary

Python schema translation rejected array-valued options received from other SDKs because option values only supported atomic types. This change recursively decodes and encodes array values, infers container element types when regenerating schema protos, and adds an ARRAY<STRING> roundtrip regression case.

With Python support in place, this also restores Debezium's primaryKeyColumns schema option, which had been removed as a temporary workaround.

Testing

• uvx tox -e py311 -- -k proto_survives_typing_roundtrip apache_beam/typehints/schemas_test.py (365 passed)
• target/.tox/py311/bin/python -m pytest -q apache_beam/typehints/schemas_test.py (759 passed, 5 skipped)
• ./gradlew :sdks:java:io:debezium:test with seven non-Docker unit classes selected (41 passed)
• ./gradlew :sdks:java:io:debezium:compileJava :sdks:java:io:debezium:spotlessJavaCheck
• YAPF and git diff --check

---

• Mention the appropriate issue in the description.
• Update CHANGES.md with noteworthy changes. Not needed for this focused bug fix.
• File an Apache Individual Contributor License Agreement. Not needed for this small change.

[gemini-code-assist]

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[github-actions]

Assigning reviewers:

R: @shunping for label python.
R: @chamikaramj for label java.

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[Abacn]

Thank you!