Create binary storage format

[onox]

glTF has several problems because it was designed for WebGL instead of OpenGL 4.x:

• Requires PNG and JPG support (needs to be decoded and do not use GPU compression) but does not support KTX textures
• Requires parsing a JSON file, which slows down loading models
• Each mesh in a model's scene may use a different vertex format. Although in practice the format of the attributes is the same for all meshes, their index type (uint16 or uint32) may differ
• No SPDX license identifier for meshes

Create a binary storage format:

• Based on document container files using the dcf-ada library (already used for locations in #35)
• Require all files stored in the container to use the "store" compression format
  • Vertex data may be compressed with Draco
• Optimized for OpenGL 4.3 or later and Vulkan
• Any software supporting this format must ignore any unknown files in the container
• TODO Add that assets can be assumed/required to be on SSDs? (No slow storage)
• TODO Support cameras, lights and speakers?
• Textures must be stored in one or more KTX files in the container
• TODO Specify PBR requirements for materials
  • TODO Specify transparency, refraction, and clear coat requirements
• ~~Vertex attributes must not be interleaved~~
  • TODO Allow quantization parameters?
• Vertex buffers and the index buffer are stored in separate files in the container
• Must contain an index buffer
• Contains a file describing the vertex format
  • Index type must be unsigned short or unsigned int
  • A vertex format has a single specific index type
• Contains a file describing the bounding boxes of meshes
• Contains a file with an array of draw commands (GL.Types.Indirect.Elements_Indirect_Command_Array)
  • TODO Multiple arrays for different pipeline state? (Opaque and transparent meshes) (in that case there may be multiple vertex formats as well)
• Contains a file describing the scene tree
  • TODO Specify how the tree must be stored (a single array of the levels or multiple levels)
• Contains a file with copyright and SPDX license identifiers of the meshes
  • TODO Contain matrices (or euler or quaternions) and/or visibility flags?
  • TODO Support multiple LoDs?
• TODO Support skinning and animation?