This simplifies the client-side API for Wayland extensions by introducing QWaylandClientExtension/QWaylandClientExtensionTemplate classes. These classes takes care of the initialization of the extension if it matches the interface name. Change-Id: I7c4fb34563563af4be072cdebda54954b79cddbe Reviewed-by: Johan Helsing <johan.helsing@theqtcompany.com> Reviewed-by: Giulio Camuffo <giulio.camuffo@kdab.com>