Toggle setting for auto uploads feature

### Is your feature request related to a problem? Please describe.
Currently, there is no easy way to disable all auto uploads and backup if a users contact book.

### Describe the solution you'd like
A switch to toggle all auto-uploads on or off, as well as contact book backups

### Describe alternatives you've considered
Turning off sync for each folder individually.

### Additional context
I have a nextcloud server running on a raspberrypi4, that is currently turned off as I am migrating to another SD card with a different partitioning setup. I started the migration a week ago, and have not yet setup nextcloud on the new SD card. Therefore, I get a notification saying that backup and sync as failed as it cannot contact the server. I am requesting an option to easily disable these features temporarily.

This feature would also benefit users who are going off of the network for a while and don't want these messages.

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