reintroduce SetMappingScale to Materials

[klepto2]

I have reported that originally here: 

But i would like to bring this up again. I have now working a lot with the polyhaven api and their textures to generate materials out of them. The textures or better the metadata of the PBR materials have a property called wideness, which for some is 1m and for others eg: 15m. Polyhaven itself use this in their blender plugin to fix the texturesize on brushes by scaling the uvs according to this wide parameter. This would be nice to have in UltraEngine itself, not only for imported materials, but also for tiling on planes etc.