Returns an entity render controller for a given entity type.
string $entity_type: The type of the entity.
Drupal\Core\Entity\EntityRenderControllerInterface An entity render controller.
\Drupal\Core\Entity\EntityManager
function entity_render_controller($entity_type) {
$info = entity_get_info($entity_type);
$class = $info['render_controller_class'];
return new $class($entity_type);
}