Support KHR_texture_transform extension for Normal and Occlusion textures

[rdeepak2002]

Normal and Occlusion textures can have texture transformations applied to them

• Example: https://github.com/KhronosGroup/glTF-Sample-Assets/tree/main/Models/TextureTransformMultiTest

I've tested these changes in my own game engine and they seem to work:

[alteous]

Thanks for your PR. I would like to hold off merging for now until I have the 2.0 code ready.