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

test/api_test.dart

@@ -5,6 +5,7 @@
 import "package:test/test.dart";
 
 import "package:inventree/api.dart";
+import "package:inventree/helpers.dart";
 import "package:inventree/user_profile.dart";
 
 
@@ -94,6 +95,9 @@ void main() {
 
         assert(!api.checkConnection());
 
+        debugContains("Token request failed: STATUS 401");
+        debugContains("showSnackIcon: 'Not Connected'");
+
       } else {
         assert(false);
       }
@@ -137,6 +141,9 @@ void main() {
       assert(api.checkPermission("stocklocation", "delete"));
       assert(!api.checkPermission("part", "weirdpermission"));
       assert(api.checkPermission("blah", "bloo"));
+
+      debugContains("Received token from server");
+      debugContains("showSnackIcon: 'Connected to Server'");
     });
 
   });