Update status codes (#307)

* Extra error info when connecting to server

* Adds accessors for various types of status codes

* Cleanup / refactor stock status codes

- No longer need to duplicate these on the app

* improvements to purchase order list

- Add option to show closed orders
- Render order status

* Add purchase order status to order detail widget

* Update release notes

* Cleanup for imports

* linting fixes

lib/widget/purchase_order_detail.dart

@@ -66,6 +66,8 @@ class _PurchaseOrderDetailState extends RefreshableState<PurchaseOrderDetailWidg
   Future<void> request(BuildContext context) async {
     await order.reload();
 
+    await api.PurchaseOrderStatus.load();
+
     lines = await order.getLineItems();
 
     completedLines = 0;
@@ -112,6 +114,12 @@ class _PurchaseOrderDetailState extends RefreshableState<PurchaseOrderDetailWidg
           title: Text(order.reference),
           subtitle: Text(order.description),
           leading: supplier == null ? null : InvenTreeAPI().getImage(supplier.thumbnail, width: 40, height: 40),
+          trailing: Text(
+            api.PurchaseOrderStatus.label(order.status),
+            style: TextStyle(
+              color: api.PurchaseOrderStatus.color(order.status)
+            ),
+          )
         )
     );