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/utils/message_extensions.dart

@@ -8,6 +8,17 @@ extension MessageLocalization on Message {
   String getLocalizedDeliveryStatus(BuildContext context) {
     final l10n = AppLocalizations.of(context)!;
 
+    // For channel messages, show echo count instead of delivery status
+    if (isChannelMessage && deliveryStatus == MessageDeliveryStatus.sent) {
+      if (echoCount == 0) {
+        return l10n.broadcast; // "Broadcast (no echoes yet)"
+      } else if (echoCount == 1) {
+        return 'Rebroadcast by 1 node';
+      } else {
+        return 'Rebroadcast by $echoCount nodes';
+      }
+    }
+
     switch (deliveryStatus) {
       case MessageDeliveryStatus.sending:
         return l10n.sending;