The initial implementation of the MeshFederation controller relies on a specific label being present on gateways used with federation (federation.maistra.io/proxy), whose value must match the name of the MeshFederation resource.  We should consider creating gateways as a part MeshFederation processing, so users do not need to know about special requirements for gateways used for federation.  We should also consider keeping the current mechanism in place (referencing an existing gateway), which gives users more control.