VOXELFORMAT: support the long way rotation in the animation

[mgerhardy]

Currently the quat lerp is taking the shortest way from src to dest. but the animation creator might have configured it to take the long way ImGuizmo doesn't support this atm

check negated quaternions for this - they are equivalent but interpolating between ones of different polarity takes the longer way

[mgerhardy]

VXA/VXR already has a property for this and SceneGraphKeyFrame contains a boolean for longRotation already.