Inconsistent folder naming for BasisU assets

[Arseny Kapoulkine]

StainedGlassLamp puts assets into glTF-KTX-BasisU folder, whereas AnisotropyBarnLamp puts them in glTF-KTX2-Basisu (note the 2. and incorrect case on u).

It would be nice to match the folder names for all variants for consistency; this helps for tooling that wants to exclude or include folders with a specific name.

[Leonard Daly (Daly Realism)]

@echadwick-wayfair : Can you address this please.

[Eric Chadwick]

Thanks for catching this! Renamed the folder in this branch: #3