set transforms using object3d vs setAttribute in look-controls

[ngokevin]

Description:

Porting some critical code to faster/cleaner object3D API for transform updates.

Changes proposed:

• Use 3js object3D API for transforms in look-controls for bit of speed.
• Don't need to re-allocate object this.savedPose every enter VR.

[dmarcos]

I have a PR that touched this logic to fix the user height issues. Some parts of this might end up obsolete. I put it on hold and I’ll submit mine today or tomorrow

[dmarcos]

#3327 delegates pose update to the VRManager from THREE that changes the object3D directly. It makes this PR redundant.