fix: read 'articulated' from PIF

VectoCore/VectoCore/InputData/FileIO/XML/Declaration/DataProvider/XMLDeclarationVehicleDataProvider.cs

@@ -1041,7 +1041,7 @@ namespace TUGraz.VectoCore.InputData.FileIO.XML.Declaration.DataProvider
 		public RegistrationClass RegisteredClass { get; }
 		public VehicleCode VehicleCode { get; }
 		public FloorType FloorType { get; }
-		public bool Articulated { get; }
+		public bool Articulated { get { return GetBool(XMLNames.Vehicle_Articulated); } }
 		public Meter Height { get; }
 		public Meter Length { get; }
 		public Meter Width { get; }