only on updates and history screen for now, but the required changes on app bar
is there.
also fix missing incognito-downloaded mode indicator on history screen
- Migrate sources filter screen to full compose
- Use standard "OK"/"Cancel" actions for delete category dialog
- Abstract some AppBar logic
- Remove some dead code
- Group related strings
* Migrate Updates screen to compose
* Review Changes + Cleanup
Remove more unused stuff and show confirmation dialog when mass deleting chapters
* Review Changes 2 + Rebase