feat: 全面改用maim_message，移除对rest的支持

src/plugins/PFC/chat_observer.py

@@ -3,7 +3,7 @@ import asyncio
 import traceback
 from typing import Optional, Dict, Any, List
 from src.common.logger import get_module_logger
-from ..message.message_base import UserInfo
+from maim_message import UserInfo
 from ...config.config import global_config
 from .chat_states import NotificationManager, create_new_message_notification, create_cold_chat_notification
 from .message_storage import MongoDBMessageStorage