feat: Allow changing languages (#1488)

Co-authored-by: validcube <pun.butrach@gmail.com>

pubspec.yaml

@@ -31,7 +31,6 @@ dependencies:
       ref: 560d21c4148b53933313573e7eafca0b0eb9aadf # Branch: specify-namespace
   flutter_cache_manager: ^3.3.0
   flutter_file_dialog: ^3.0.2
-  flutter_i18n: ^0.34.0
   flutter_local_notifications: ^16.1.0
   flutter_localizations:
     sdk: flutter
@@ -68,12 +67,14 @@ dependencies:
   timezone: ^0.9.0
   url_launcher: ^6.1.10
   wakelock_plus: ^1.1.3
+  slang: ^3.25.0
+  slang_flutter: ^3.25.0
+  language_code: ^0.3.1
 
 dev_dependencies:
   build_runner: any
   flutter_lints: ^3.0.1
   injectable_generator: ^2.1.5
-  json_serializable: ^6.6.1
 
 flutter:
   uses-material-design: true
@@ -83,3 +84,6 @@ flutter:
         - asset: fonts/custom-icons.ttf
   assets:
     - assets/i18n/
+
+flutter_localizations:
+  sdk: flutter