Display serial number for serialized stock

lib/inventree/stock.dart

@@ -280,6 +280,14 @@ class InvenTreeStockItem extends InvenTreeModel {
 
   bool isSerialized() => serialNumber != null && quantity.toInt() == 1;
 
+  String serialOrQuantityDisplay() {
+    if (isSerialized()) {
+      return 'SN ${serialNumber}';
+    }
+
+    return '${quantity}';
+  }
+
   String get locationName {
     String loc = '';
 

lib/widget/part_stock_detail.dart

@@ -91,7 +91,7 @@ class PartStockList extends StatelessWidget {
     return ListTile(
       title: Text("${item.locationName}"),
       subtitle: Text("${item.locationPathString}"),
-      trailing: Text("${item.quantity}"),
+      trailing: Text(item.serialOrQuantityDisplay()),
       leading: FaIcon(FontAwesomeIcons.mapMarkerAlt),
       onTap: () {
         _openItem(context, item.pk);