New3dapi, rename to .shaders.DefaultShader, move Light and add direction and angle

- Use negative LightsCount to disable lighting (allowing zero lights)
- Rename TestShader to shaders.DefaultShader
- Move Light to .g3d and add direction and angle
- Default DefaultShader.ignoreUnimplemented to true for now

Let's not spend too much time on creating some uber default shader for now and indeed use TestShader for now.