Fixing SkeletonUtils retarget() and retargetClip() functions

This thread points to the old example that used to exist, showing how to retarget BVH (and! It was based on BVH, so I think that’s a clue, because any time I tried to apply BVH to a GLTF model it was similarly messed up):

And what I mean by “messed up” is this happens: