Add KTX2/Basis sample

[lilleyse]

Now that KTX2/Basis support is being added to CesiumJS in CesiumGS/cesium#9040 we should add a sample that uses KTX2/Basis textures.

@YoussefV Take a look at createBatchedTextured as a reference point for the new sample. Instead of using data/wood_red.jpg the new sample would use data/wood_red.ktx2. You'll mostly be working in 3d-tiles-samples-generator.ts, createBuilding.ts, and createGltf.js.

The project is midway through changing from JavaScript to TypeScript so apologies if it's a little messy.

[YVin3D]

searching createBatchedTextured in this repo yields no results, I can see one usage of data/wood_red.jpg here. But not sure how it relates to createBatchedTextured

[lilleyse]

@YoussefV not sure why your search didn't pick it up, but you can find occurrences in 3d-tiles-samples-generator.ts

[lilleyse]

Yeah sorry if my message was unclear, createBatchedTextured is a function not a file name (in case you were doing a file search)

[YVin3D]

Yeah that's weird... Would I be replacing the .jpg or creating a new BaseColorType for a CompressedTexture?

[lilleyse]

Just talked offline - but yes, the latter.