Add 3D capabilities

[LeHaine]

Base Goals:

• [ ] Directional light, point light, spot light
• [x] 3D related mesh building / generating
• [x] Extend SceneGraph with 3D related nodes
• [x] glTF / glb models loading & handling

Stretch goals (maybe in the future)

• [ ] PBR related shaders, lighting, and handling
• [ ] Instanced drawing
• [ ] LOD handling
• [ ] Deferred shading
• [ ] Screen-space Ambient Occlusion (SSAO)

[LeHaine]

202 adds a bunch of 3D related graphics handling with very basic lighting