Stock barcode fix (#232)

* API: Provide more info in error messages

* Fix support for legacy stock item custom barcodes

* Refresh display after assigning barcode

* Update release notes

* Fix for scanning unkown barcode

- Modern API returns slightly different data

* Fix for scanning unkown barcode

- Modern API returns slightly different data

* Update release notes

lib/widget/dialogs.dart

@@ -185,10 +185,10 @@ Future<void> showServerError(String url, String title, String description) async
 /*
  * Displays an error indicating that the server returned an unexpected status code
  */
-Future<void> showStatusCodeError(String url, int status) async {
+Future<void> showStatusCodeError(String url, int status, {String details=""}) async {
 
   String msg = L10().responseInvalid;
-  String extra = "${L10().statusCode}: ${status}";
+  String extra = url + "\n" + "${L10().statusCode}: ${status}";
 
   switch (status) {
     case 400:
@@ -231,6 +231,11 @@ Future<void> showStatusCodeError(String url, int status) async {
       break;
   }
 
+  if (details.isNotEmpty) {
+    extra += "\n";
+    extra += details;
+  }
+
   showServerError(
     url,
     msg,

lib/widget/location_display.dart

@@ -456,7 +456,7 @@ class _LocationDisplayState extends RefreshableState<LocationDisplayWidget> {
 
         if (InvenTreeAPI().supportModernBarcodes) {
           tiles.add(
-            customBarcodeActionTile(context, location!.customBarcode, "stocklocation", location!.pk)
+            customBarcodeActionTile(context, this, location!.customBarcode, "stocklocation", location!.pk)
           );
         }
       }

lib/widget/part_detail.dart

@@ -698,7 +698,7 @@ class _PartDisplayState extends RefreshableState<PartDetailWidget> {
 
     if (InvenTreeAPI().supportModernBarcodes) {
       tiles.add(
-        customBarcodeActionTile(context, part.customBarcode, "part", part.pk)
+        customBarcodeActionTile(context, this, part.customBarcode, "part", part.pk)
       );
     }
 

lib/widget/stock_detail.dart

@@ -802,10 +802,23 @@ class _StockItemDisplayState extends RefreshableState<StockDetailWidget> {
       )
     );
 
-    if (InvenTreeAPI().supportModernBarcodes) {
-      tiles.add(customBarcodeActionTile(context, item.customBarcode, "stockitem", item.pk));
+    if (InvenTreeAPI().supportModernBarcodes || item.customBarcode.isEmpty) {
+      tiles.add(customBarcodeActionTile(context, this, item.customBarcode, "stockitem", item.pk));
+    } else {
+      // Note: Custom legacy barcodes (only for StockItem model) are handled differently
+      tiles.add(
+          ListTile(
+              title: Text(L10().barcodeUnassign),
+              leading: Icon(Icons.qr_code, color: COLOR_CLICK),
+              onTap: () async {
+                await item.update(values: {"uid": ""});
+                refresh(context);
+              }
+          )
+      );
     }
 
+
     // Print label (if label printing plugins exist)
     if (labels.isNotEmpty) {
       tiles.add(