Add ability to specify to "rerender" last message instead of sending new.

[idchlife]

We should store last message id in memory in format like "TG_USER_ID-LAST_BOT_MESSAGE_ID".

I think getting bot message id is possible after sending with sendMessage api method.

respond do
  # Here your response
  
  tg_rerender true
end

Which would edit message user respon

[notetell]

Telegram API allows to send either text, or use specific API methods for sending specific media type with text caption, or send just a media file without text. Also we cant send a message that will be formatted like "text above - image - text below" for example. That means that if our output has an attachment - it will be sent as a separate message.

Because of this we will accept that if response has multiple outputs OR if output has attachment - than output's id will not be saved, also we will delete previously recorded message id - so we don't have a situation where we rerender the message that is way above. We will only rerender messages that have one output.