refactoring of custom connector for telegram

[essare-rimaz]

• functionality can be inherited from Input/Output telegram channel
• follow this tutorial
• the main goal of this custom connecter is to have a clean implementation of url type buttons (instead of changing in rasa source code)
• the methods to be implemented in this new connector are

  
  elif button_type == "inline_url":
  reply_markup = InlineKeyboardMarkup()
  button_list = [
      InlineKeyboardButton(
          s["title"], url=s["url"]
      )
      for s in buttons
  ]
  reply_markup.row(*button_list)

elif button_type == "vertical_url": reply_markup = InlineKeyboardMarkup() [ reply_markup.row( InlineKeyboardButton(s["title"], url=s["url"]) ) for s in buttons ]