[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/inventree/model.dart

@@ -66,7 +66,7 @@ class InvenTreeModel {
   String get WEB_URL => "";
 
   // Return the "model type" of this model
-  String get MODEL_TYPE => "";
+  static const String MODEL_TYPE = "";
 
   // Helper function to set a value in the JSON data
   void setValue(String key, dynamic value) {