This corresponds to the |info| field in EVP_PKEY_ASN1_METHOD, as well
as the generic use of OBJ_nid2ln() as a one line description.
We also add the base functionality to make use of this field.
Fixes#14514
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/14656)