This patch implements a new interface class
KoColorDisplayRendererInterface. This interface can be passed to widgets
that are able to render color on screen, so that they could use it to
apply display profiling as needed.

There is also a KoDumbColorDisplayRenderer::instance() placeholder object
that can be used by default and that would convert the color using usual
KoColor::toQColor() method, which is effectively just a sRGB.