ui: Show call graphs, inheritance trees and include trees for active symbol (issue 249 337)

* Added TrailLayouter with Sugiyama dependency layouting
* Layouter supports horizontal and vertical layouts
* Added basic ui to graph view for showing incoming and outgoing paths
* Added depth slider, with infinity at maximum
* Disable trail ui when not available
* Added trail messages to undo stack and only use last one when undoing
* Added QtGraphLineBezier for trail graphs and refactored other line types
* Disabled edge activation for trail layouts, shown only visually
* Highlight all connected edges when hovering a node in trail layout
* Use different color when highlighting call edges for better contrast
* Fixed BucketLayouter issue when edge does not leave node
* Increased click area for angled edges

bug id = 249 337

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src/lib_gui/qt/view/graphElements/QtGraphNode.h

@@ -1,6 +1,8 @@
 #ifndef QT_GRAPH_NODE_H
 #define QT_GRAPH_NODE_H
 
+#include <functional>
+
 #include <QGraphicsItem>
 
 #include "utility/math/Vector4.h"
@@ -93,6 +95,8 @@ protected:
 	virtual void mouseMoveEvent(QGraphicsSceneMouseEvent* event);
 	virtual void mouseReleaseEvent(QGraphicsSceneMouseEvent* event);
 
+	void forEachEdge(std::function<void(QtGraphEdge*)> func);
+
 	void notifyEdgesAfterMove();
 
 	void setStyle(const GraphViewStyle::NodeStyle& style);