Deprecate node_type_get_names

Given the function is just

  return array_map(function ($bundle_info) {
    return $bundle_info['label'];
  }, \Drupal::service('entity_type.bundle.info')->getBundleInfo('node'));

this could be added as a convenience method to EntityTypeBundleInfo so you can call e.g.

$labels = \Drupal::service('entity_type.bundle.info')->getBundleLabels('node');

I like that approach, adding a new method to an interface is always contentious but let's see.