Add localization support for German, Spanish, French, and Italian

- Updated localization files for French, Croatian, Italian, Slovenian to include translations for German, Spanish, French, and Italian.
- Added new methods for handling drawing messages sent to the public channel in multiple languages.
- Enhanced the Contact model to identify public channels using a dedicated method.
- Implemented echo detection for public channel messages, including tracking and reporting of echoes.
- Updated BLE response handling to support echo detection and tracking of sent messages.
- Modified UI components to reflect new localization strings and echo statuses.

lib/widgets/contacts/contact_tile.dart

@@ -719,7 +719,7 @@ class ContactTile extends StatelessWidget {
                     ),
                   ],
                   // Room Login button for room contacts (except Public Channel)
-                  if (contact.type == ContactType.room && contact.advName != 'Public Channel') ...[
+                  if (contact.type == ContactType.room && !contact.isPublicChannel) ...[
                     const SizedBox(height: 24),
                     SizedBox(
                       width: double.infinity,
@@ -739,7 +739,7 @@ class ContactTile extends StatelessWidget {
                     ),
                   ],
                   // Delete Contact button (for all contact types except Public Channel)
-                  if (contact.advName != 'Public Channel') ...[
+                  if (!contact.isPublicChannel) ...[
                     const SizedBox(height: 12),
                     SizedBox(
                       width: double.infinity,