Screentime improvements:

- Support apps when enabled
- Remove the first step when adding deadline rules, user picks one of three buttons initially instead. This now allows blocking, allowing, and updating restrictions as part of the same rule.
- Remove the first step when adding timers, the user picks one of two buttons initially instead
- Remove the edit/save stages when editing timers, just save immediately
- Fix the timers page allowing to add more timers than the quota, which would fail