Add setting current context of types

[Abstract-X]

Description

If we try to get the current update from context, we get None:

from aiogram import Bot, Dispatcher, executor
from aiogram.types import Message

bot = Bot("...")
dispatcher = Dispatcher(bot)

@dispatcher.message_handler()
async def handle_message(message):
    current_message = Message.get_current()
    print(current_message)  # None

executor.start_polling(dispatcher)

After the changes presented in PR, we get the current update without errors:

@dispatcher.message_handler()
async def handle_message(message):
    current_message = Message.get_current()
    print(current_message)  # {"message_id": 1206, "from": {"id": 650535775, ...
    print(message is current_message)  # True

Type of change

• Bug fix (non-breaking change which fixes an issue)

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code