Didn't know how to pass a ROS data type (the feedback msg) as a qt signal type so did it this way. The arg is needed as a signal must get a type, so I'm just using QString as a dummy arg.

It might be possible to create signals with msg types using something like self.sig_foo=Signal(VersualServoiActionFeedback). But that needs to happen on the widget class so would need to restructure the plugin to make that work.