Create agl-cluster-demo-receiver repository

Please create an apps/agl-cluster-demo-receiver repository on AGL Gerrit. It will be used to hold the cluster demo receiver application for the Wayland virtual display streaming from the IVI board. The intent is to use it in both the Flounder 6.0.x and master / Guppy trees via a recipe that will be added in the new meta-agl-cluster-demo layer.  I'm open to suggestions on alternate naming.