Added imgui debug dialog for render statistics

src/libslic3r/Technologies.hpp

@@ -11,6 +11,8 @@
 #define ENABLE_SELECTION_DEBUG_OUTPUT 0
 // Renders a small sphere in the center of the bounding box of the current selection when no gizmo is active
 #define ENABLE_RENDER_SELECTION_CENTER 0
+// Shows an imgui dialog with render related data
+#define ENABLE_RENDER_STATISTICS 1
 
 
 //====================