Support KTX2 and Basis Texture compression

[devshgraphicsprogramming]

Description

Initial idea was to just have a .basis texture loader, but now KTX2 has it!

Description of the related problem

https://github.com/buildaworldnet/IrrlichtBAW/issues/342

Solution proposal

Pimp our KTX loader to support KTX2 and Binomial's Basis-U

Additional context

https://www.khronos.org/news/press/khronos-ktx-2-0-textures-enable-compact-visually-rich-gltf-3d-assets

[devshgraphicsprogramming]

also see if there exists a way to parallelize loading (will probably need to implement memory mapped files for this)