OpenXR 6DOF Controller improvements

[MortimerGoro]

• Fix HVR height on 6DOF controllers
• Add HVR 6DOF mapping
• Improve beam transform on Oculus 3D model
• Add SetBeamTransform (previously it could only be passed in the constructor)

[MortimerGoro]

Closing this PR as I'll push a new one with some other fixes and improvements