Create Visual Unit Tests for newly supported VertexFormat type

1) Need to enhance the TriangleTest visual unit test to check for valid / invalid conditions when normals are provided

2) Another good unit test will be to generate a mesh using a function, and then compare the rendering of that mesh using smoothing groups versus computed, user-defined surface normals (using a reasonable tolerance since the averaged face normals that you get from smoothing groups are usually only an approximation to the actual surface normal you would compute).