Add basic changed tracking and message box when loading while having changes

source/armarx/navigation/graph/Graph.cpp

source/armarx/navigation/graph/Visu.cpp

source/armarx/navigation/graph/Visu.h

...x/navigation/gui-plugins/LocationGraphEditor/GuiGraph.cpp

...arx/navigation/gui-plugins/LocationGraphEditor/GuiGraph.h

...cationGraphEditor/LocationGraphEditorWidgetController.cpp

...LocationGraphEditor/LocationGraphEditorWidgetController.h

...i-plugins/LocationGraphEditor/widgets/EdgeTableWidget.cpp

...-plugins/LocationGraphEditor/widgets/VertexDataWidget.cpp

...ui-plugins/LocationGraphEditor/widgets/VertexDataWidget.h

...plugins/LocationGraphEditor/widgets/VertexTableWidget.cpp

...i-plugins/LocationGraphEditor/widgets/VertexTableWidget.h

...igation/gui-plugins/LocationGraphEditor/widgets/utils.cpp

...avigation/gui-plugins/LocationGraphEditor/widgets/utils.h