In many locales format should be "surname name" (which is BTW more useful for sorting), so it's better to make locale as incoming optional parameter and return full_name depending on locale.

Codecov Report

Merging #949 into master will decrease coverage by 0.11%.
The diff coverage is 100%.

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I don't think this information is in python locale module though?
It seems to have been in CLDR at some point, but not anymore, if I understand it correctly. In any case, I view this as just a simpler version of User.name method that works exactly the same way, only ensuring that returned names are consistent in style (I feel that mentioning some users via "@username" and others via "name" is unintuitive and doesn't look all that well in group chats).

@graynk you're right, for some strange reason, there is no such info in Python's locale module.

Looks good to me. Closes #943

thank you for your contribution