Add option to enable auto backups each day - let type in a CT time for now

[szaimen]

• block login for 5min or so before the backup starts and delete all sessions

• update mastercontainer first: create a file that the update was run. if the file exists, continue directly with updating the and backing up the rest...

• only show the option after the initial backup was created

• Also make clear that this automatically start the containers after the backup is done which will automatically update them (except the mastercontainer)

• Needs to remove all sessions when the job starts in the background so that you don't get into any race conditions (and also set auth state to logged out?)

• hide start containers button when auto backup is running (starting all containers directly after borgbackup container should prevent that (maybe delete the sessions again after the backup container was started to make sure))

• Allow to select the borg archive to restore from #39

• if backup creation fails, add file to nextcloud container so that it skips any automatic update #67

• https://unix.stackexchange.com/a/94521

• inform about the state of the backup (wait until the nextcloud container is running again qfter backup xontainer was started and all other containers were started) and then send the notification

• may also update all nextcloud apps on startup (not if backup was restored)

[szaimen]

    # 1. delete all sessions and block login
    # 2. After 5min waiting, Update the mastercontainer (and check if watchtower is running)
    # 3. create a file which can be checked for: if the file is present, start with the process at this step after the update and skip waiting for the next day
    # 4. shut down all containers
    # 5. create backup 
    # 6. start all containers (because it will wait until backup container has finished)
    # 7. unblock login
    # 8. after nextcloud was started, send message if backup was successful or not