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
This lets us make it more consistent with the Compose screens for now. Maybe it'll return in the future.
This also includes making the AboutController a full Compose controller with a new abstracted TopAppBar composable.