FakeInput: add support for pointer move with absolute coordinates
Summary: For remote desktop support, we need to move with the pointer using absolute positin.
Test Plan: I tested this with xdg-desktop-portal-kde and krfb and it worked.
Reviewers: davidedmundson, graesslin, zzag
Reviewed By: davidedmundson, zzag
Subscribers: graesslin, zzag, kde-frameworks-devel
Tags: Frameworks
Differential Revision: https://phabricator.kde.org/D18114