Pull request/Issue to tarantool: api for getting tuple field names from box_tuple_format

There's no way to work with box_tuple_format using the tarantool's C api which is need to stabilize the Tuple::as_named_buffer which is hidden behind the picodata feature.

We need to create a pull request to https://github.com/tarantool/tarantool or at least create an issue for it

See !219 (merged)