#2309379 Moved drupal_mail to MailManager::mail

from:
  fqn: 'fn:drupal_mail'
to:
  fqn: 'service:plugin.manager.mail'
from:
  fqn: 'fn:drupal_html_to_text'
to:
  fqn: '\Drupal\Core\Mail\MailFormatHelper::htmlToText'
from:
  fqn: 'fn:drupal_wrap_mail'
to:
  fqn: '\Drupal\Core\Mail\MailFormatHelper::wrapMail'