VTK Chart Overlay Doesn't work with VTK 9

[estan (Elvis Stansvik)]

@estan

BTW I agree that it would be good with some kind of warning/error mechanism for when you enable some piece of functionality (e.g. RenderingContext2D ), but there’s no implementation module for it (e.g. RenderingContextOpenGL2 ) enabled, since that’s sort of a non-sensical config.

…though I guess in theory you could provide your own implementation, but I’m not sure that is so common.