Entity.Add does not have single component overload.


entity.Add doesn't have a overload for 1 component. it requires at least two.
```cs
    [Query][None<WindowHandle>]
    public static void AttachWindowHandler(ref Window window, [Data] Entity entity, [Data] World world)
    {
        var silkWindow = CreateHandle(window, entity);
        entity.Add(silkWindow); // error.
    }
    
```