Feature request: Ability to backup/restore

[mizzunet]

Ability to backup and restore data. So I could import Bit Warden password to Passwd.

Thanks

[Tisckkytt]

Not just that, I'm actually surprised not to see a local backup/restore functionality present already. It's a must have for any apps, let alone a password manager.

[gargakshit]

Started in features/import_export branch.

[tusharsadhwani]

@Tisckkytt feel free to add any other features that you'd like by creating a PR.