Improve Quests Functionality Overall

Bug fixes:
- quests succeed properly and show up in success sections
- quests expire properly after 7 days (users can redo them)
- users actually  gain experience from success
Additional features:
- Fitbit subscriptions work; only fetch new data if fitbit has pinged us letting us know the user has recently synced
- Implement quest alerts on home screen
- Quest sucess/fail is only evaluated if there is new data. ie if a user hasn't synced all day, a quest won't be evaluated for pass/fail!