Enhance broadcast message handling to support multiple content types

- Updated the process_broadcast_message_handler to determine the content type of incoming messages (text, photo, video, etc.) and store relevant data in the state.
- Implemented new methods in MessageQueueManager for queuing various media types, improving the flexibility of the broadcast system.
- Adjusted confirmation prompts to provide a concise message preview, enhancing user experience.
- Added localization for the new confirmation prompt in both English and Russian.

locales/en.json

@@ -155,6 +155,7 @@
 
   "admin_broadcast_enter_message": "Enter the broadcast message (HTML supported):",
   "admin_broadcast_confirm_prompt": "You are about to send the following message:\n\n{message_preview}\n\nConfirm sending?",
+  "admin_broadcast_confirm_prompt_short": "The message above will be sent. Confirm?",
   "broadcast_target_all_button": "👥 All",
   "broadcast_target_active_button": "✅ Active",
   "broadcast_target_inactive_button": "⌛ Inactive",

locales/ru.json

@@ -155,6 +155,7 @@
 
   "admin_broadcast_enter_message": "Введите сообщение для рассылки (HTML поддерживается):",
   "admin_broadcast_confirm_prompt": "Вы собираетесь отправить следующее сообщение:\n\n{message_preview}\n\nПодтверждаете отправку?",
+  "admin_broadcast_confirm_prompt_short": "Сообщение выше будет отправлено. Подтвердить отправку?",
   "broadcast_target_all_button": "👥 Все",
   "broadcast_target_active_button": "✅ Активные",
   "broadcast_target_inactive_button": "⌛ Неактивные",