Model rigid body tree motion given task-space inputs

**Library:**Robotics System Toolbox / Manipulator Algorithms

The Task Space Motion Model block models the closed-loop task-space motion
of a manipulator, specified as a `rigidBodyTree`

object. The motion model behavior
is defined using proportional-derivative (PD) control.

[1] Craig, John J.
*Introduction to Robotics: Mechanics and Control*. Upper Saddle River,
NJ: Pearson Education, 2005.

[2] Spong, Mark W., Seth Hutchinson,
and Mathukumalli Vidyasagar. *Robot Modeling and Control*. Hoboken, NJ:
Wiley, 2006.