Notifications & warning dialog

notifications
dialog with warnings produced by slicing is shown before exporting

src/imgui/imconfig.h

@@ -113,7 +113,12 @@ namespace ImGui
     const char PrinterSlaIconMarker = 0x6; 
     const char FilamentIconMarker   = 0x7; 
     const char MaterialIconMarker   = 0x8;
-
+	const char CloseIconMarker      = 0xB;
+	const char CloseIconHoverMarker = 0xC;
+	const char TimerDotMarker       = 0xE;
+	const char TimerDotEmptyMarker  = 0xF;
+	const char WarningMarker        = 0x10;
+	const char ErrorMarker          = 0x11;
 //    void MyFunction(const char* name, const MyMatrix44& v);
 
 }