WIP: Use OrbGL as render context
- Use OrbGL as render context
- Impl Renderer trait for OrbGL Canvas with render_path and render_shape
- Enum with (render) PathSegement like MoveTo, ArcTo, DrawImage, ...
- RenderShapes Rectangle, Image, Text
- Different helper structs like Brush, Border, Thickness, ...
- Removed old render objects
- Feature "orbgl_render" to switch from OrbGL CairoRenderEngine to OrbGLREnderEngine