Have an auto backup mechanism for the LMDb database

[samwiseg0]

Is your feature request related to a problem? Please describe

In migrating my system to a fresh OS I was unable to restore a backup of that database. I came to learn that LMDb is architecture dependent and I would have to convert the database from 32bit to 64bit. More info here #192

Describe the solution you'd like

I believe providing an auto DB backup mechanism could solve multiple issues.

Auto backups could provide:

• Backups of the DB. This can also be invoked before a moonraker update.
• A method for users to migrate to other architectures without having to first dump the db before migrating. This would solve Moonraker's LMDB database files are architecture dependant #192
• In the event of corruption there would be backups of the data
• If an upgrade fails there is a path to downgrade.

Describe alternatives you've considered

Using an external script to dump and manage database backups. This presents some challenges since ideally you would want to ensure that moonraker is not actively using the DB before pulling the data.

Additional information

No response