[BUG] RestClientPE controller models broken when token refresh is called

[LL928]

RestClientPE controller models change from PE to CE version when refresh method is called. For example, calling get_user_device after refresh result in an attribute error:

AttributeError: 'DeviceControllerApi' object has no attribute 'get_user_devices_using_get'

RestClientPE is missing overloading for refresh method:

    def refresh(self):
        super(RestClientPE, self).refresh()
        self.__load_controllers()