Draft: Add support for activating the applications we launch
Adds the necessary bits for implementing xdg_activation_v1 for applications launched with global shortcuts.
It adds a KGlobalAccelInterfaceV3 that the compositor should implement and will be used to request a token. This token is forwarded to the processes we launch either through dbus activation or as the environment variable.
Draft because the KWin side is missing.
Edited by Aleix Pol Gonzalez