Enable parsing and handling of TrafficAreas (aka RoadRanges)

openSCENARIO XML v1.3 introduces TrafficAreaActions, allowing to specify an Area in within Vehicles are placed with a certain distribution. A cornerstone of this definition is a construct named RoadRange, which can be seen as an spatial interval on a road without (necessarily) limiting it to a certain lane. Right now, there is no support for this type, making it impossible to create a (map agnostic) implementation of the TrafficAreaAction on top of Mantle.