feat(i18n): add French language support and enhance localization

- Introduced French as a supported language across the application, updating locale files and adding translations for various components.
- Enhanced language handling logic to accommodate French, ensuring proper detection and fallback mechanisms.
- Updated UI elements to include French language options, improving accessibility for French-speaking users.
- Refactored SEO handling to include French in hreflang links, enhancing search engine indexing for multilingual content.
- Added new scripts for managing French translations and ensuring consistency across language files.

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

@@ -0,0 +1,29 @@
+{
+    "friends": {
+        "kicker": "Communauté",
+        "intro": "Amitiés, demandes ouvertes et contacts continus en un seul endroit.",
+        "title": "Amis",
+        "stats": {
+            "existing": "Existant",
+            "open": "Ouvrir"
+        },
+        "tabs": {
+            "existing": "Existant",
+            "rejected": "Rejeté",
+            "pending": "En attente",
+            "requested": "Demandé"
+        },
+        "actions": {
+            "end": "Beenden",
+            "accept": "Annehmen",
+            "reject": "Ablehnen",
+            "withdraw": "Retirer"
+        },
+        "headers": {
+            "name": "Name",
+            "age": "Alter",
+            "gender": "Geschlecht",
+            "actions": "Actes"
+        }
+    }
+}