Locale switch (#200)

* Add function to set app locale

* Setting for selecting app language

- Adds requirement for "flutter_localized_locales"
- Change main app to stateless

* Reload entire app tree when language is changed

* Update release notes

* linting

pubspec.lock

@@ -284,6 +284,13 @@ packages:
     description: flutter
     source: sdk
     version: "0.0.0"
+  flutter_localized_locales:
+    dependency: "direct main"
+    description:
+      name: flutter_localized_locales
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "2.0.3"
   flutter_markdown:
     dependency: "direct main"
     description: