New API: +hb_ot_layout_feature_get_name_ids() +hb_ot_layout_feature_get_characters()
* hb_ot_layout_feature_get_characters * hb_ot_layout_feature_get_name_ids However HarfBuzz currently doesn't expose an API for retrieving the actual information associated with NameId from the `name` table and that should be done separately.