feat(admin): add user vocab course management functionality

- Implemented `getUserVocabCourses` and `getVocabCourseForAdmin` methods in `AdminController` to allow admins to retrieve enrolled vocab courses for users and specific course details, respectively.
- Updated `adminRouter` to include new routes for accessing user vocab courses and course details.
- Enhanced `AdminService` with methods to list user-enrolled vocab courses and retrieve course information with lessons, ensuring proper access control.
- Improved `VocabService` to support the new functionalities, including attaching language names to course data.
- Updated UI components in `UsersView` to reflect changes, including error handling and loading states for course retrieval, along with localization updates for new features.

backend/services/adminService.js

@@ -1973,6 +1973,36 @@ class AdminService {
             throw e;
         }
     }
+
+    async adminListUserEnrolledVocabCourses(requesterHashedId, targetHashedId) {
+        if (!(await this.hasUserAccess(requesterHashedId, 'useradministration'))) {
+            throw new Error('noaccess');
+        }
+        const vocab = new VocabService();
+        try {
+            return await vocab.listEnrolledVocabCoursesForUser(targetHashedId);
+        } catch (e) {
+            if (e.status === 404) {
+                throw new Error('notfound');
+            }
+            throw e;
+        }
+    }
+
+    async adminGetVocabCourseWithLessons(requesterHashedId, courseId) {
+        if (!(await this.hasUserAccess(requesterHashedId, 'useradministration'))) {
+            throw new Error('noaccess');
+        }
+        const vocab = new VocabService();
+        try {
+            return await vocab.adminGetCourseWithLessonsForStaff(Number(courseId));
+        } catch (e) {
+            if (e.status === 404) {
+                throw new Error('coursenotfound');
+            }
+            throw e;
+        }
+    }
 }
 
 export default new AdminService();