Location::attr_names iterates by name. Requested:
- attribute names in a chosen
H5_index_t and H5_iter_order_t, as iter_visit offers for links
- opening an attribute by index,
H5Aopen_by_idx
- an attribute's info,
H5Aget_info_by_name, at least corder_valid and corder
Location::attr_namesiterates by name. Requested:H5_index_tandH5_iter_order_t, asiter_visitoffers for linksH5Aopen_by_idxH5Aget_info_by_name, at leastcorder_validandcorder