introduce a collapsable route figure

In future we want to show multiple routes in the diagram at the same time when users open the context file in the editor.

1. DblClick on a context file will open up the diagram editor and display all routes of the context
2. the routes are collapsable figures and via dbl-click on a route you can "Go Into" this route and that will open another diagram editor for that specific route. (this is already provided logic by graphiti)
3. we want to see connections between routes if applicable