Rename SUJ GetVoltages to use CRTK like names and automatically publish

[adeguet1]

[adeguet1]

The C++ object is a vctDoubleVec, not the type expected for measured_js. Plus measured_js only has position, velocity and effort. This raises the question of adding some types and CRTK commands. For example, we might add a motor or actuator state with name(), encoder(), voltage(), current(), enabled() vectors and the commands measured_as and setpoint_as. We could also add measured_jA to get just current in Amps for the joints and create a crtk_msg::SensorStamped message with header, name, value.