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/controllers/authController.js

@@ -29,6 +29,8 @@ class AuthController {
         } catch (error) {
             if (error.message === 'credentialsinvalid') {
                 res.status(404).json({ error: error.message });
+            } else if (error.message === 'userblocked') {
+                res.status(403).json({ error: error.message });
             } else {
                 res.status(500).json({ error: error.message });
             }