Create class to get current domain

[protitude]

Create quick and easy class to grab the current domain. Maybe under access/src/Plugin. Could place other misc classes under here as well.

  // Get current domain
  $domain = \Drupal::config('domain.settings');
  $token = \Drupal::token();
  $domainName = t("[domain:name]");
  $current_domain_name = Html::getClass($token->replace($domainName));