These changes make the navigation and status bar accessible from within fullscreen applications by allowing the user to tap on the top or tap or drag on the bottom of the screen.
Also, since the top panel is now over top of all fullscreen applications, this moves the action drawer swipe area back into the status bar.

This avoids having to completely load the quicksettings, status bar,
media widget, and notifications list from scratch when the view changes.
We now have a single instance of each component which is reparented to
the new view (portrait/landscape).
Fixes https://invent.kde.org/plasma/plasma-mobile/-/issues/406