update cartion editor for package

lib/pages/carton/custom_duty_addition.dart

@@ -35,11 +35,18 @@ class _CustomDutyAdditionState extends State<CustomDutyAddition> {
         shipmentRateModel.rate.customDuties.map((e) => e.clone()).toList();
 
     for (var p in customDuties) {
+      p.qty = 0;
       if (widget.customDuties.any((e) => e.id == p.id)) {
         p.isChecked = true;
       } else {
         p.isChecked = false;
       }
+
+      widget.customDuties.forEach((vp) {
+        if (p.id == vp.id) {
+          p.qty = vp.qty;
+        }
+      });
     }
 
     if (mounted) {
@@ -87,6 +94,7 @@ class _CustomDutyAdditionState extends State<CustomDutyAddition> {
         callBack: () {
           List<CargoType> _cargos =
               customDuties.where((c) => c.isChecked).toList();
+
           if (_cargos.isEmpty) {
             showMsgDialog(context, 'Error', "Please select the cargo type");
             return;