remove debug code
ScalarsForColorMapping is now responsible for lookup table setup

* move scattered lut configuration code to ScalarsForColorMapping
* RenderedData's are still responsible for applying the lut to the relevant object (mapper or texture), as this depends on the render setup (specific for triangle meshes, images, ..)
* removes some duplicated updates (now more explicit in ScalarsForColorMapping, e.g. beforeRender() )
fix: call render() when toggling legend visibility in the UI
fix: missing ScalarVisibilityOn in VertexComponentMapping
don't recreate the mapper for configuration changes in RenderedPolyData