add build step for flutter web, add persistent pagination in the traction list

lib/services/data_service/data_service_traction.dart

@@ -13,7 +13,7 @@ extension DataServiceTraction on DataService {
   Future<void> fetchTraction({
     bool hadOnly = false,
     int offset = 0,
-    int limit = 50,
+    int limit = 100,
     String? locoClass,
     String? locoNumber,
     bool mileageFirst = true,

lib/services/distance_unit_service.dart

@@ -158,7 +158,7 @@ class DistanceFormatter {
     return NumberFormat(pattern);
   }
 
-  String _formatMilesChains(double miles, {int decimals = 1}) {
+  String _formatMilesChains(double miles) {
     final totalChains = miles * DistanceUnitService.chainsPerMile;
     var milesPart = totalChains ~/ DistanceUnitService.chainsPerMile;
     final chainRemainder =