Handle Wayland change sets in AbstractOutput
Summary:
Move Wayland change set handling to AbstractOutput and create
virtual functions to call into the hardware implementation
Reviewers: KWin, davidedmundson
Reviewed By: KWin, davidedmundson
Subscribers: kwin
Tags: KWin
Maniphest Tasks: T10016
Differential Revision: https://phabricator.kde.org/D16785