Improve EXPLAIN AST to pass 481/484 tests

- Fix ilike/notILike function name casing
- Add PREWHERE clause support
- Add SAMPLE clause support with SampleRatio formatting
- Update OptimizeQuery with suffix for FINAL/DEDUPLICATE flags
- Fix SetQuery, ShowQuery, RenameQuery output formats
- Add SHOW CREATE TABLE/DATABASE special handling
- Add parametric function support (separate ExpressionLists)
- Fix SystemQuery to output table/database identifiers
- Add TTL support in ALTER commands
- Fix RENAME_COLUMN to output new column name
- Normalize DETACH_PARTITION to DROP_PARTITION, CLEAR_INDEX to DROP_INDEX
- Add INTO OUTFILE clause support
- Add column COMMENT support
- Fix BinaryExpr alias handling
- Add tuple with expressions as Function tuple output
- Add named window (WINDOW clause) support

The remaining 3 failing tests (dateadd, datesub) require complex
semantic transformations where ClickHouse transforms dateAdd() into
plus() with toInterval functions.

Author: claude