89 torque current conversion

[SteveNguyen]

No description provided.

[askuric]

It looks good to me, but I cannot really test it. :D

Will this HWI modification allow setting the torque, velocity and position target values separately?

At the moment we had the position control pass through the JointCommands topic, but the velocity and torque commands were 0.

Will the target velocity and target torque be separate messages or will they be within the JointCommands too?
In practice it would be better that they are not, as the torque target will be used as feed-forward for the gravity compensation.

Ideally, all the target values (pos, vel and torque) would be in JointCommands (and we would use only one of them given the current mode of opertaion), but we would have another interface for the feed-forward terms.
And ideally, we would have another set of entries in the EtherCAT communication that would correspond to the feed-forward terms.