feat(localization): expand language support and enhance UI for user settings

- Added support for additional UI locales including Cebuano and Spanish, improving accessibility for a broader user base.
- Updated language selection components in the AppHeader and SettingsWidget to reflect new language options, enhancing user experience.
- Enhanced localization of various UI elements across components, ensuring consistent language representation and improved user engagement.
- Implemented logic to synchronize user language preferences with backend settings, providing a seamless experience when changing languages.

frontend/src/i18n/locales/de/friends.json

@@ -1,6 +1,12 @@
 {
     "friends": {
+        "kicker": "Community",
+        "intro": "Freundschaften, offene Anfragen und laufende Kontakte an einem Ort.",
         "title": "Freunde",
+        "stats": {
+            "existing": "Bestehend",
+            "open": "Offen"
+        },
         "tabs": {
             "existing": "Bestehende",
             "rejected": "Abgelehnte",