cdp1_msled

[NRRPLT-4958,NRRPLT-5894] New/changed model files to demo collision detection and reponse on the mouse foot in the cdp1 experiment.
The file model_tactile.sdf is the new variant of the cdp1 forelimb model with collision geometry attached to the fore limb. The foot is held in the arresting mechanism via collisions.
The sled model is fitted with collision geometry as well. It is used in both the previous model variant and the one in this commit. In the old variant the collision geometry has zero impact since it is the only collision geometry in the world.

Change-Id: I87f1062090a1939c48f2d00362e1e2d045d41a43