list traction and add leaderboard panel

lib/objects/objects.dart

@@ -105,7 +105,7 @@ class LocoSummary {
     locoType: json['loco_type'],
     locoClass: json['loco_class'],
     locoNumber: json['loco_number'],
-    locoName: json['loco_name'],
+    locoName: json['loco_name'] ?? "",
     locoOperator: json['loco_operator'],
     locoNotes: json['loco_notes'],
     locoEvn: json['loco_evn'],
@@ -224,4 +224,3 @@ class Leg {
         .toList(),
   );
 }
-