Rename database table and related classes from MaterialsToBeDeleted to MaterialsTypeToBeDeleted for better semantic clarity.
Changes:
- Rename MaterialsToBeDeletedDAO class to MaterialsTypeToBeDeletedDAO
- Update all SQL queries to reference MaterialsTypeToBeDeleted table
- Update import statement in material_status_validator.py
- Update documentation comments
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>