Use M3 theme, switch to Material Dialogs

• Add Monet dynamic colors on the app's onCreate()
• Set parent in styles.xml to Theme.Material3.DayNight.NoActionBar
• In AlertDialogFragment, line 67, it uses MaterialAlertDialogBuilder instead
• In the About and About KDE fragments, it uses the M3 elevated style instead of outlines
• In edit_text_alert_dialog_view.xml, it uses the default theme style instead of specifying the one from MaterialComponents
• Added a todo in the settings fragment: Preference dialogs don't yet use the M3 style, and the only current way to do it would be to do a custom one in the theme which doesn't sound great
  • See https://github.com/material-components/material-components-android/issues/2732

It complements !273 (closed), though the way that merge request accomplishes color theming is the one from before the onCreate dynamics color method