Besides the refactoring these improvements:
* Track last push distributor and reset settings and subscription on any
incompatible change (ie. uninstall)
* Only update (push) notification settings on server if needed
* Allow to only fetch notifications for one account (the one for which a
push message was received)
This is (also) the revival of
https://github.com/tuskyapp/Tusky/pull/3642
It's not really well tested so far. (Ie. with two or more accounts or
two or more push providers.)
- Move all database queries off the ui thread - this is a massive
performance improvement
- ViewModel for MainActivity - this makes MainActivity smaller and
network requests won't be retried when rotating the screen
- removes the Push Notification Migration feature. We had it long
enough, all users who want push notifications should be migrated by now
- AccountEntity is now immutable
- converted BaseActivity to Kotlin
- The header image of Accounts is now cached as well
