Format a username.
By default, the passed-in object's 'name' property is used if it exists, or else, the site-defined value for the 'anonymous' variable. However, a module may override this by implementing hook_user_format_name_alter(&$name, $account).
$account: The account object for the user whose name is to be formatted.
An unsanitized string with the username to display. The code receiving this result must ensure that check_plain() is called on it before it is printed to the page.
function user_format_name($account) {
$name = !empty($account->name) ? $account->name : config('user.settings')
->get('anonymous');
drupal_alter('user_format_name', $name, $account);
return $name;
}