This PR fixes some issues founded during my re-launch of the Pilot URJC in foxy:
Removes node_name field in the ChangeMode.Request srv.
Fixes an issue with the ros2_knowledge_graph whereby an instance of the graph does not take the changes of another instance. I had to use the blackboard of the BTs to share an instance of the graphs between the different nodes.
This PR fixes some issues founded during my re-launch of the Pilot URJC in foxy: