Save account passwords with settings

[cm-mc]

Is your feature request related to a problem? Please describe.
If you have multiple accounts (10, atm...), it can get tiresome to go through all passwords if you need to reinstall.

Describe the solution you'd like
Add an option to save passwords along setting (in same or separate file).

Describe alternatives you've considered
If adding encryption code is beyond scope, just add option to save them in plain text, and keep it disabled by default, with a warning about plain text.

Additional context
About saving plain text passwords: you may just want to keep a local copy of your settings, in case you need to reinstall, in which case, if the device is ever compromised to the point they can be read from a plain text file, that will be the least of your problems.

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Unrelated, but not worth opening an issue for, imv:
Portuguese (pt-pt) language translation for end-to-end encryption setting says "OenPGP", missing a "p".

[cketti]

I'd rather not add support for exporting passwords in plain text. See #4700 (comment)

I think encrypting all account passwords with a backup password is the way to go.

[cm-mc]

Yeah, well, nvm; I've found a more suitable alternative, in the end. But, if you're adamant storing plain text passwords is that serious a security risk, better not trusting them to 3rd party mail servers, to begin with (or even use e-mail, at all), because they're way more at risk of a server attack/leak than phone hacks.

Cheers.

(Btw, Titanium Backup only works on rooted phones; that's also a "security risk", for some...)