Optionally back up the DB before saving

[Fry-kun]

Is your feature request related to a problem? Please describe. This morning I couldn't open the DB I use daily. Old backup opens up just fine, so the current copy got corrupted somehow.

Describe the solution you'd like While saving the DB, the existing copy should be optionally copied over into a _bak file so it's easier for users to recover with a recent backup.

Describe alternatives you've considered

Additional context