SCA client reference binding vaue should have special characters to denote it is not an actual reference URI

In the sca-client-impl module the RemoteServiceInvocationHandler.createEndpointReference method creates a "dummy" reference value to set for the reference name prepended with the string "sca.client":

componentReference.setName("sca.client." + service.getName());

However, it is possible that "sca.client" could be in the name of an actual reference/serice, so I'm suggesting we use "$sca.client$." rather than the existing string to avoid any conflicts/confusion in debugging.