Various asset improvements: Wavefront OBJ texture options and possible PBR, Spine fre

[DP News-Robot]

Various improvements to various asset formats: We now implement Wavefront OBJ texture options. They are all parsed correctly, and the scale, offset, clamp are actually handled. We can also generate PBR (physical) materials when reading Wavefront OBJ files. This feature is for now experimental, and you have to toggle global WavefrontPhongMaterial in X3DLoadInternalOBJ unit to …