Add Vocab Trainer feature with routing, database schema, and translations

- Introduced Vocab Trainer functionality, including new routes for managing languages and chapters.
- Implemented database schema for vocab-related tables to ensure data integrity.
- Updated navigation and UI components to include Vocab Trainer in the social network menu.
- Added translations for Vocab Trainer in both German and English locales, enhancing user accessibility.

frontend/src/router/socialRoutes.js

@@ -5,6 +5,11 @@ import GuestbookView from '../views/social/GuestbookView.vue';
 import DiaryView from '../views/social/DiaryView.vue';
 import ForumView from '../views/social/ForumView.vue';
 import ForumTopicView from '../views/social/ForumTopicView.vue';
+import VocabTrainerView from '../views/social/VocabTrainerView.vue';
+import VocabNewLanguageView from '../views/social/VocabNewLanguageView.vue';
+import VocabLanguageView from '../views/social/VocabLanguageView.vue';
+import VocabSubscribeView from '../views/social/VocabSubscribeView.vue';
+import VocabChapterView from '../views/social/VocabChapterView.vue';
 
 const socialRoutes = [
     {
@@ -49,6 +54,36 @@ const socialRoutes = [
         component: DiaryView,
         meta: { requiresAuth: true }
     },
+    {
+        path: '/socialnetwork/vocab',
+        name: 'VocabTrainer',
+        component: VocabTrainerView,
+        meta: { requiresAuth: true }
+    },
+    {
+        path: '/socialnetwork/vocab/new',
+        name: 'VocabNewLanguage',
+        component: VocabNewLanguageView,
+        meta: { requiresAuth: true }
+    },
+    {
+        path: '/socialnetwork/vocab/subscribe',
+        name: 'VocabSubscribe',
+        component: VocabSubscribeView,
+        meta: { requiresAuth: true }
+    },
+    {
+        path: '/socialnetwork/vocab/:languageId',
+        name: 'VocabLanguage',
+        component: VocabLanguageView,
+        meta: { requiresAuth: true }
+    },
+    {
+        path: '/socialnetwork/vocab/:languageId/chapters/:chapterId',
+        name: 'VocabChapter',
+        component: VocabChapterView,
+        meta: { requiresAuth: true }
+    },
 ];
 
 export default socialRoutes;