[refactor] Scan improvements (#577)

* Handle error on unexpected barcode response

* Add ManufacturerPart detail view

* Support barcode scanning for manufacturer part

* Refactoring for null checks

* Ignore selected errors in sentry

* Fix API implementation for ManufacturerPart

* Update release notes

* More error handling

* Decode quantity betterer

* Refactoring

* Add option to confirm checkin details

* Improve response handlign

* Cleanup

* Remove unused imports

* Fix async function

* Fix for assigning custom barcode

* Handle barcode scan result for company

* Fix

* Adjust scan priority

* Refactoring MODEL_TYPE

- Use instead of duplicated const strings

* @override fix

lib/widget/stock/location_display.dart

@@ -246,7 +246,7 @@ class _LocationDisplayState extends RefreshableState<LocationDisplayWidget> {
 
       if (widget.location != null) {
 
-        String model_type = api.supportsModernLabelPrinting ? InvenTreeStockLocation().MODEL_TYPE : "location";
+        String model_type = api.supportsModernLabelPrinting ? InvenTreeStockLocation.MODEL_TYPE : "location";
         String item_key = api.supportsModernLabelPrinting ? "items" : "location";
 
         _labels = await getLabelTemplates(

lib/widget/stock/stock_detail.dart

@@ -298,7 +298,7 @@ class _StockItemDisplayState extends RefreshableState<StockDetailWidget> {
     // Request information on labels available for this stock item
     if (allowLabelPrinting) {
 
-      String model_type = api.supportsModernLabelPrinting ? InvenTreeStockItem().MODEL_TYPE : "stock";
+      String model_type = api.supportsModernLabelPrinting ? InvenTreeStockItem.MODEL_TYPE : "stock";
       String item_key = api.supportsModernLabelPrinting ? "items" : "item";
 
       // Clear the existing labels list