* Fixes#7776
Implement QRegularExpression::escape within Tools::convertToRegex to allow usage on older Qt versions.
Also wrap EXACT_MODIFIER patterns in a non-capture group to prevent misinterpreted regex.
- Default backupFilePath is '{DB_FILENAME}.old.kdbx' to conform to existing standards
- Implement backupPathPattern tests.
- Show tooltip on how to format database backup location text field.