Added full support of `Bot API 7.8 <https://core.telegram.org/bots/api-changelog#july-31-2024>`_

- Added the field :code:`has_main_web_app` to the class :class:`aiogram.types.user.User`,
  which is returned in the response to :class:`aiogram.methods.get_me.GetMe`.
- Added the parameter :code:`business_connection_id` to the methods
  :class:`aiogram.methods.pin_chat_message.PinChatMessage`
  and :class:`aiogram.methods.unpin_chat_message.UnpinChatMessage`,
  allowing bots to manage pinned messages on behalf of a business account.