Entity Query support for config entities

Similar to EntityFieldQuery has been rewritten config entities now also have support to be queried using a query.

Before

$enabled_views = array();
foreach (entity_load_multiple('view') as $view) {
  if ($view->isEnabled()) {
    $enabled_views[] = $view->id();
  }
}

After (with entity query)

$enabled_views = Drupal::entityQuery('view')
  ->condition('disabled', FALSE)
  ->execute();