Missing possibility to define the DefaultRoutingBehavior

Depending on the scenario description, there could be different standards for the "default behavior", which kicks in as soon as a route is depleted. We already now about two descriptions, one using "stop where you are" and the other (openSCENARIO) using "go on randomly". In the discussion of openSCENARIO and the AssignRouteAction, we realized that there is no way to tell the environment what the default behavior should be.