cleaning up duplicate code in PositionalAudio and 'unsetting' filter

MeshStandardMaterial: remove reflectivity, reflectivityMap

cleaning up duplicate code in PositionalAudio and enabling the 'unsetting' of a filter with setting a null filter

Fix for undefined resetBlendWeights method Exception

Fix for exception with 1 keyframe animations

Refactor OrbitControls

Removing both THREE.AnimationHandler.play and THREE.AnimationHandler.stop as they include "keyframe animation" in global THREE.AnimationHandler.update routine, which expects resetBlendWeights method that's missing for keyframe animations. I also don't see any use for it, as whole animation lifecycle is in this case handled inside KeyFrameAnimation.

In the end this causes undefined method exceptions in AnimationHandler.js#L208
if used in coonection with both KeyFrameAnimation and AnimationHandler for skinnned meshes.

Animations with only one key throw exception because next frame is not available.

Dev audio #7485

adding back updated load function to Audio for compatibility, AudioBuffer now only take the Audio context instead of the listener at creation