Solid color support, project sampling support

The first iteration of supporting solid color for meshes has been added. This is for meshes that do not contain a texture but instead use a material with a solid color. Some examples are available here (you may need to import into blender and then export as glb.)

https://quaternius.com/

A reminder that for the glb/gltf embedded model, it still only supports a single texture and do not include other textures (such as normal map, bump map, etc.) I am working to see if multiple textures can be supported. That being said, a single texture will still perform better, since it will not create a renderer state switching to change textures.

Project sampling for embedded textures is now also supported (e.g. nearest vs trilinear). Currently, the sampling change will only take effect during runtime, until C3 adds the support for finding project sampling settings in editor mode.

If you see an older model which is using C3 image texture appear as white, this usually means that the gltf used does not include a textured material for the mesh, so you will need to add one to the model (using blender, etc.)

I have also focused on using 'regular' z axis rather than normalized z axis, because it's more intuitive for all 3d cases and also adds support for changing project fov.

So, it's recommended to set 3DObject projects to 'regular' z-axis settings.