Stock location scan (#169)

* Add action for scanning a stock location into another location

* Adds barcode scan handler for new functionality

* Handle scanning of stock location

* Cleanup

* Refactor existing barcode scanning functions

- Will require extensive testing and validation

* Add entry to release notes

* Delete dead code

* Improved ordering based on stock quantity

* Bug fix for 'adjustStock' function

* Improve error responses for barcode scanning

* Improve error responses for barcode scanning

* Remove old debug statements

* Add some extra explanatory texts

* Icon change

* Fixes for unit tests

* Adds extra functionality for user profile manager

* Refactor barcode code - do not rely on BuildContext

* Adds initial unit testing for barcode scanning

- Work on mocking barcode data
- Add hooks for testing snackBar and audio files

* Linting fixes

* More barcode unit tests

* Cleanup unit tests for barcode

* Remove unused import

* Handle HTTPException in API

* Improvements for API unit testing

* Unit testing for scanning item into location

* Add unit test for scanning in items from a location context

* Unit test for scanning location into parent location

* Improve feedback for barcode scanning events

lib/api.dart

@@ -413,6 +413,8 @@ class InvenTreeAPI {
           break;
       }
 
+      debug("Token request failed: STATUS ${response.statusCode}");
+
       return false;
     }
 
@@ -1017,14 +1019,16 @@ class InvenTreeAPI {
         }
 
         if (statusCode != null) {
-
           // Expected status code not returned
           if (statusCode != _response.statusCode) {
             showStatusCodeError(url, _response.statusCode);
           }
         }
       }
-
+    } on HttpException catch (error) {
+      showServerError(url, L10().serverError, error.toString());
+      response.error = "HTTPException";
+      response.errorDetail = error.toString();
     } on SocketException catch (error) {
       showServerError(url, L10().connectionRefused, error.toString());
       response.error = "SocketException";