So far we've been copying protocol specifications from wayland-protocols
repo to kwayland repo. The main issue with copying is that we have to
keep xml files in sync manually. A better approach would be to use xml
specs straight from wayland-protocols package.
Test Plan: Compiles.
Reviewed By: KWin, romangg, davidedmundson
Subscribers: davidedmundson, apol, romangg, asturmlechner, kde-frameworks-devel
Differential Revision: https://phabricator.kde.org/D22216