Add password for SSH, AWS and GDrive config

[JoeZiminski]

This PR adds the option to encrypt the RClone config file containing SSH, AWS or GDrive connection information (e.g. private key, passwords, access tokens). The main changes are:

1. SSH, AWS and GDrive RClone configs are now stored in separate .conf files (previously, the RClone default to store everything in RClone's rclone.conf was used. This is still kept for local_filesystem for backwards compatibility.
2. There is now an option during set up connections (via Python API or TUI) to encrpy the config file. Doing so will encrypt the file using the operating systems credential manager.

This required quite a lot of refactoring to the setup connection functions (API and TUI) as well as the internal calls to rclone. Now, these calls are wrapped in some functionality that handles unencrypting the rclone config if required.

Tests and documentation have been updated.

This implementation is okay but there is still room for improvement. However, as this PR is pretty big and we just need to get this out, these are reversed for the future (#636).

[niksirbi]

I tried this with Google Drive on MacOS.

All went well (incl. authentication) until I trying to encrypt the credentials using the built-in macOS' security tool (as prompted). I'm pasting the exception as screenshot, because my terminal didn't allow me to properly copy the exception text.

I tried several times, including setting from scratch, but to no avail.

[niksirbi]

Turns out it was the Rclone version, thanks for the tip @JoeZiminski.

The problem went away by updating Rclone from 1.65 to 1.73.

[ishan372or]

@JoeZiminski I tested this on Windows 11 (rclone v1.73.0).
Google Drive setup and OAuth worked fine, and the encryption prompt appeared.
However, encryption fails at the final step with:

[JoeZiminski]

Hey @ishan372or thanks for this! I'm a bit stumped, the only clue is that the drive is missing from your path e.g. Khan\... rather than C:\Users\Khan\..., so maybe something is breaking in the path handling somewhere. Could I check the full path to your user folder Khan?

[JoeZiminski]

Hi @ishan372or don't worry, I can replicate now I guess you have a space somewhere along that path? thanks! This is a very useful case that was not properly handled, will push a fix

[JoeZiminski]

Hi @ishan372or thanks again for testing, could you try again with the latest version of this branch?

[ishan372or]

@JoeZiminski , I pulled the latest commits and retested windows 11. It ran succesfully this time.

[JoeZiminski]

Perfect, thanks @ishan372or! BTW I think #669 is complete, GitHub is having CI issues ATM but once they are fixed and the tests can run will be good to merge. Thanks a lot for that

[ishan372or]

thanks. Happy to help