Backport #97843 to 26.1: accept COMMENT before AS SELECT in view parser

[alexey-milovidov]

Summary

• Accept COMMENT clause before AS SELECT in the view parser for forward compatibility
• Newer ClickHouse versions (26.2+) may format views with COMMENT before AS SELECT
• This parser-only change ensures views created on newer versions can be loaded by this release
• No formatter changes — the formatter continues to output COMMENT after AS SELECT

Ref #97843

Changelog category (leave one):

• CI Fix or improvement (not a bug fix)

Changelog entry (a user-readable short description of the changes that goes to CHANGELOG.md):

Accept COMMENT before AS SELECT in view parser for forward compatibility with newer versions.

🤖 Generated with Claude Code

[clickhouse-gh]

Workflow [BackportPR], commit [2e6f576]

Summary: ❌

job_name	test_name	status	info	comment
Integration tests (amd_asan, db disk, old analyzer, 2/6)		failure
	test_replicated_database/test.py::test_alter_rename	FAIL	cidb
	test_replicated_database/test.py::test_lag_after_recovery	FAIL	cidb
	test_replicated_database/test.py::test_system_database_replicas_with_ro	FAIL	cidb
	test_replicated_database/test.py::test_block_system_database_replicas	FAIL	cidb
	test_replicated_database/test.py::test_timeseries	FAIL	cidb
	test_replicated_database/test.py::test_mv_false_cyclic_dependency	FAIL	cidb
	test_replicated_database/test.py::test_ignore_cluster_name_setting	FAIL	cidb
Integration tests (amd_asan, db disk, old analyzer, 4/6)		failure
	test_database_hms/test.py::test_hive_catalog_url_parsing	FAIL	cidb
Integration tests (amd_tsan, 5/6)		failure
	test_storage_iceberg_no_spark/test_writes_statistics_by_minmax_pruning.py::test_writes_statistics_by_minmax_pruning[s3-1]	FAIL	cidb
	test_storage_iceberg_no_spark/test_writes_statistics_by_minmax_pruning.py::test_writes_statistics_by_minmax_pruning[s3-2]	FAIL	cidb
	test_storage_iceberg_no_spark/test_writes_statistics_by_minmax_pruning.py::test_writes_statistics_by_minmax_pruning[azure-1]	FAIL	cidb
	test_storage_iceberg_no_spark/test_writes_statistics_by_minmax_pruning.py::test_writes_statistics_by_minmax_pruning[azure-2]	FAIL	cidb
	test_storage_iceberg_no_spark/test_writes_statistics_by_minmax_pruning.py::test_writes_statistics_by_minmax_pruning[local-1]	FAIL	cidb
	test_storage_iceberg_no_spark/test_writes_statistics_by_minmax_pruning.py::test_writes_statistics_by_minmax_pruning[local-2]	FAIL	cidb
	test_storage_iceberg_no_spark/test_writes_multiple_files.py::test_writes_multiple_files[local-1]	FAIL	cidb
	test_storage_iceberg_no_spark/test_writes_multiple_files.py::test_writes_multiple_files[local-2]	FAIL	cidb
	test_storage_iceberg_no_spark/test_writes_multiple_threads.py::test_writes_multiple_threads[s3-1]	FAIL	cidb
	test_storage_iceberg_no_spark/test_writes_multiple_threads.py::test_writes_multiple_threads[s3-2]	FAIL	cidb
	4 more test cases not shown
Integration tests (amd_tsan, 6/6)		failure
	test_database_hms/test.py::test_hive_catalog_url_parsing	FAIL	cidb