Add Mlang based materials

[Helco]

We finally switch to another shader system where variants can be more easily defined, even if we have to write the shader language first.

This PR will be mostly a rework, replacing the old, pure GLSL shaders with a Mlang based approach. To further test it out the envmap materials should be implemented.

CI will fail as the native shaderc library currently cannot be loaded on Linux.

A rough roadmap necessary for merging:

Mlang/MlangMaterial features

• Block names
• Shader Option Mask (and related deduplication)
• (Postponed) Merged attribute layouts
• Attribute mapping by name
• (Maybe) Generic Mesh class with better instancing support

Places to integrate (and therefore testing)

• ModelViewer
• ActorViewer
• WorldViewer
• SceneEditor
• ActorRenderer
• WorldRenderer
• ModelRenderer
• ECSExplorer
• EffectEditor
• ParticleBehaviourModel
• UI batcher
• Debug renderers
  • Skeleton
  • Lines
  • TriangleLine
  • OctahedronLine
  • HexahedronLine
  • BoxLine
  • DiamondSphereLine
  • Grid
  • Plane
  • Icon

Postponed components (create issue on merge)

• zzmaps
• SparkMaterial
• EffectMaterial

Fixes #267