At this point the `UserProfile` component needed a `userInfo` of type `AccountUserInfo` to render. However, we need to consider the case when we view a profile and we don't know the username on the client (an anonymous user). `stringForUserExplicit` is a function that handles this case for us and this also allows us to switch the `userInfo` prop type to be the more permissive `UserInfo` type
Depends on D9094