Refactor MongoDB handling for cleaner and safer code.

Replaced deprecated `default` with `default_factory` for ObjectId to ensure proper instantiation. Simplified message insertion by directly calling `to_mongo()` inline, reducing temporary variable usage.

cbh/api/message/db_requests.py

@@ -26,6 +26,5 @@ async def create_message_obj(chat_id: str, message: CreateMessageRequest) -> Mes
                            author=message.author,
                            text=message.text,
                            moduleResponse=message.moduleResponse)
-    t = message.to_mongo()
-    await settings.DB_CLIENT.messages.insert_one(t)
+    await settings.DB_CLIENT.messages.insert_one(message.to_mongo())
     return message

cbh/core/database.py

@@ -7,13 +7,12 @@ from bson import ObjectId
 PyObjectId = Annotated[str, BeforeValidator(str)]
    
 class MongoBaseModel(BaseModel):
-    id: Optional[PyObjectId] = Field(alias="_id", default=ObjectId())
+    id: Optional[PyObjectId] = Field(alias="_id", default_factory=ObjectId)
 
     model_config = ConfigDict(
         populate_by_name=True,
         arbitrary_types_allowed=True,
         json_encoders={PyObjectId: str},
-        response_by_alias=False
     )
 
     def to_mongo(self):