Set transform in AbstractWaylandOutput
Summary:
Move the Wayland output device and output transform calls from DRM backend
to AbstractWaylandOutput. This leaves still some loose ends that need to be
tied up later. On failed commit we want to fall back to last working state
and orientation getter in general needs some more refactoring.
Test Plan: Compiles.
Reviewers: KWin
Subscribers: kwin
Tags: KWin
Maniphest Tasks: T11670
Differential Revision: https://phabricator.kde.org/D25504