SAF implementation for access of protected data in `/android/data`

### Is your feature request related to a problem?
Since the new Android update(update to Android 11, the Android/data path is not accessible by default for the nextcloud app, this causes issues for auto upload of files

### Describe the solution you'd like
A SAF implementation where users can grant access to the protected resources and the app can return back to normal from Google's hoops lol

### Describe alternatives you've considered
Manual backup of data but that is not up to date, in event a factory reset needs to be done there is a possibility that data would be lost