More general send_message

[SiriusKoan]

The send_message method is only available for pure text. So there is no way to send photo, sticker, etc. unless using _send method. Maybe we need a general send_message method for multiple message types?

I think I can help to do this, and I have come up with two ways to implement it.

1. Combine all types of message to one method send_message (use parameter to choose type)
2. Split the method to send_message, send_photo, etc.

If there is anything I can do, please tell me.