Allow Nexus model binding to empty model paths

The Nexus' WebSocket endpoint /bindModel/ currently has its route specified as "/bindModel/:componentPath/:modelPath". In cases where a model binding needs to address the entirety of a components model, the modelPath segment of the URL is empty, e.g. "/bindModel/some.component.path/". However, requests without the modelPath segment do not trigger the endpoint. The solution to this issue is presumably to add another endpoint and connecting it to the same request handler.