Vertex color support for 3DObject

Support color vertex for 3DObject. 3DObject must include vertex colors in the gltf/glb

• New effect parameter: enable vertex color
• New 3DObject ACE: enable vertex color
• A new main.js is required in projects to support vertex color, see the main.js in 3d-object-vertex-color.c3p
• The vertex colors _must_ be in the format of float vec3 (e.g. no alpha color)

Thanks to PixelMetal for the help of providing vertex color models to test.