feat(Moderation): enhance moderation reporting and user feedback

- Added user blocking checks in authentication and reporting processes, returning appropriate error responses.
- Expanded moderation report functionality to include new target types and optional fields for reports.
- Implemented a new API endpoint to retrieve the count of open moderation reports.
- Enhanced frontend components to allow users to report profiles, images, and guestbook entries, with corresponding UI updates.
- Updated internationalization files to include new strings for reporting features in both German and English.

backend/middleware/authMiddleware.js

@@ -10,6 +10,9 @@ export const authenticate = async (req, res, next) => {
     if (!user) {
         return res.status(401).json({ error: 'Unauthorized: Invalid credentials' });
     }
+    if (!user.active) {
+        return res.status(403).json({ error: 'Unauthorized: User blocked' });
+    }
     try {
         await updateUserTimestamp(user.id);
     } catch (error) {