Add tests for CLEAR COLUMN IN PARTITION in SummingMergeTree

[CarlosFelipeOR]

Summary

• Add engines/tests/summing_merge_tree/ test suite covering SummingMergeTree zero-row deletion behavior
• Tests cover the regression found in ClickHouse upstream: CLEAR COLUMN IN PARTITION on SummingMergeTree does not trigger zero-row deletion after OPTIMIZE FINAL (regression since 25.8) ClickHouse/ClickHouse#101953
• Two scenarios xfailed pending upstream fix:
  • CLEAR COLUMN IN PARTITION does not trigger zero-row deletion after OPTIMIZE TABLE FINAL (regression since 25.8)
  • CLEAR COLUMN validation inconsistency between explicit and auto-detected summing columns

Test plan

• zero_row_deletion_with_update — passes on all versions
• zero_row_deletion_with_clear_column — xfail on >=25.8 (upstream issue)
• clear_column_validation_consistency — xfail on all versions (upstream issue)

[Selfeer]

Please review that my changes didn't break your tests - afterwards it's approved from my side

[Selfeer]

The test also lacks requirements