Local api fix
This pull request add the possiblity to set local velocity references for Cartesian task.
While this was already possible using the topic by changing the frame_id entry of the message (as suggested by @alaurenzi), a method for the C++/Python API was missing.
This is now done through a flag which is also recognized by the cartesian tasks properties. The property is called use_local_velocity, it can be set through service, in the yaml file, or via C++/Python API. Is set to True, the frame_id is ignored when using the topic (maybe we can add a ROS info if needed)
Hi @EnricoMingo I find it a bit confusing / error prone that a setter method works differently based on a flag that is set elsewhere (and not directly in the method's signature)
Do you suggest putting these frag directly in the reference setters methods?