Add detection and automatic repair for FTS4 (Full-Text Search) index
corruption, which can occur even when PRAGMA integrity_check passes.
New functions:
- CheckFTS(): Validates FTS4 index integrity using SQLite's integrity-check command
- DoFTSRebuild(): Rebuilds corrupted FTS4 indexes using SQLite's rebuild command
Enhanced existing commands:
- 'check' (option 3): Now includes FTS integrity checking
- 'reindex' (option 6): Now checks FTS indexes and rebuilds if corruption detected
- 'automatic' (option 2): Checks FTS after repair/reindex and automatically rebuilds if damaged
Refactored FTS table query into reusable FTS_TABLE_QUERY constant for maintainability.
Fixes: https://github.com/ChuckPa/DBRepair/issues/269
