MeasureGui: Add UMF folder icon

Co-Authored-By: Max Wilfinger <6246609+maxwxyz@users.noreply.github.com>

src/Mod/Measure/Gui/AppMeasureGui.cpp

@@ -87,6 +87,7 @@ PyMOD_INIT_FUNC(MeasureGui)
     // instantiating the commands
     CreateMeasureCommands();
 
+    MeasureGui::ViewProviderMeasureGroup               ::init();
     MeasureGui::ViewProviderMeasureBase                ::init();
     MeasureGui::ViewProviderMeasure                    ::init();
     MeasureGui::ViewProviderMeasureAngle               ::init();