PyBullet silently discards wrong Nullspace parameters for inverse kinematics

[marcbone]

If you set the inverse kinematics parameters for null space control (lowerLimits,upperLimits,jointRanges,restPoses) to the wrong size, then pybullet will just use the normal inverse kinematics and ignores that you actually wanted to have the null-space IK.

This is already happening in the panda_sim.py example. The robot hat 9 DoFs (7 + 2 for the gripper) but as the limits, ranges and rest poses are of size 7, PyBullet does not use the null-space-IK.

I think the function should return an error instead.