Fixes rendering of gamut masks, drops KisGamutMaskViewConverter
requested to merge amedonosova/krita:shape-masks-rendering-gamut-mask-fix into kazakov/shape-masks-rendering-392242
I have refactored gamut mask rendering to work with the shape masks rendering fix. Rotation also works. I have dropped KisGamutMaskViewConverter entirely, as we can now do without it.