Add 'all' content type for message_handler

[vovkapultik]

If you want to handle all types of content it's quite worthless job to do, I'd like you to consider adding 'all' in a content_types options as aiogram's (async botapi wrapper) devs have done

[Badiboy]

utils.content_type_media
utils.content_type_service

PS. Not an issue.

[coder2020official]

+Agree