Getting a translated field value sometimes fails

#1969728: Implement Field API "field types" as TypedData Plugins stumbled over this problem and had to create the following work-a-round:

          if ($entity instanceof EntityNG || $entity instanceof EntityBCDecorator) {
            // @todo $entity->getTranslation()->get($name) sometimes fails,
            // because Entity\Translation::getPropertyDefinitions() is empty() ??
            try {
              $entities_items[$id] = $entity->getTranslation($langcode)->get($field_name);
            }
            catch (\InvalidArgumentException $e) {
              break;
            }
          }

Let's fix this here once the issue is done.