ui: added icon colors to ColorScheme

This change introduces the qt utility function colorizePixmap() for colloring icons in different colors for different
color schemes.

src/lib/component/view/GraphViewStyle.h

@@ -40,6 +40,8 @@ public:
 
 		std::string color;
 		std::string textColor;
+		std::string iconColor;
+		std::string hatchingColor;
 
 		std::string shadowColor;
 		int shadowBlurRadius;
@@ -55,8 +57,6 @@ public:
 		bool fontBold;
 
 		Vec2i textOffset;
-
-		bool undefinedPattern;
 	};
 
 	struct EdgeStyle