add label to rows in EntityListController

EntityListController::buildRow() takes care of adding operations to the row, but it doesn't add the label.

I am struggling to understand why this is. Surely more entities you'd want to list would have labels? Not having this means that EntityListController isn't usable as a list controller OOTB. It would be good DX if EntityListController were reasonably usable for basic entities.

This quick debug output confirms that all the entity types that DON'T have labels also don't use a list controller, so having the label in this class wouldn't have a negative impact:

  $labels = array();
  foreach (entity_get_info() as $type => $entity_info) {
    $label = isset($entity_info['entity_keys']['label']) ? $entity_info['entity_keys']['label'] : 'NOLABEL';
    $list_controller = isset($entity_info['controllers']['list']) ? $entity_info['controllers']['list'] : "NOLIST";
    
    $labels[$type] = "$label - $list_controller";
  }
  dsm($labels);

Furthermore, it would allow the removal of this method in VocabularyListController and probably quite a few similar copies elsewhere:

  /**
   * {@inheritdoc}
   */
  public function buildRow(EntityInterface $entity) {
    $row['label'] = $this->getLabel($entity);
    return $row + parent::buildRow($entity);
  }