Update center #25
Description
After adding version checks (app updates), themes (#23) and languages (#24), which all can be updated, there is a need for a central "update center". Implement a new tab in the tabbed settings menu (#22) from which the user can select all the updates to perform and press one big beautiful update button. Just in the style of the app, the animation and progress/result/log etc. should be displayed beautifully.
Create a good "subscription"/config based approach for this. Create an "interface" which an updater-function can "implement" and then simply be added to a config for which updates to include in the update center. We are aiming for a no-redundancy SPOT (single point of truth) design!