Put the agent at an absolute place, facing an absolute way.
Mirrors tbp/monty/frameworks/actions/actions.py::SetAgentPose. This is the
action a goal-reaching policy ends with: everything else is a nudge, and this
is the one that says "be exactly here".
The rotation is a wxyz quaternion, which is Monty's order for poses and
therefore this port's, as Monty.Geometry.Rotation stores it.