Barcode refactor (#363)

* Move barcode.dart

* Fix

* Refactoring barcode scanner code:

- Abstract the "controller" class (for future development)
- Break barcode scanning code out into multiple files
- Add CameraBarcodeController class (qr_code_scanner)

* Add await

* Make barcode scan delay configurable

* remove unused import

* Handle camera exceptions

* Improve sequencing for camera scanner

- Show loading overlay
- Prevent reload if view is no longer mounted

* Update docstring

* Update release notes

lib/settings/settings.dart

@@ -4,8 +4,10 @@ import "package:package_info_plus/package_info_plus.dart";
 
 import "package:inventree/app_colors.dart";
 import "package:inventree/l10.dart";
+
 import "package:inventree/settings/about.dart";
 import "package:inventree/settings/app_settings.dart";
+import "package:inventree/settings/barcode_settings.dart";
 import "package:inventree/settings/home_settings.dart";
 import "package:inventree/settings/login.dart";
 import "package:inventree/settings/part_settings.dart";
@@ -68,6 +70,14 @@ class _InvenTreeSettingsState extends State<InvenTreeSettingsWidget> {
                   Navigator.push(context, MaterialPageRoute(builder: (context) => HomeScreenSettingsWidget()));
                 }
               ),
+              ListTile(
+                title: Text(L10().barcodes),
+                subtitle: Text(L10().barcodeSettings),
+                leading: FaIcon(FontAwesomeIcons.barcode, color: COLOR_ACTION),
+                onTap: () {
+                  Navigator.push(context, MaterialPageRoute(builder: (context) => InvenTreeBarcodeSettingsWidget()));
+                }
+              ),
               ListTile(
                 title: Text(L10().part),
                 subtitle: Text(L10().partSettings),