Allow OBJ_create() to create an OBJ and NID with a NULL OID

Allow OBJ_create() to create an OBJ and NID with a NULL OID

We already permit this in crypto/objects/objects.txt, but not programatically,
although being able to do so programatically would be beneficial.

Reviewed-by: Dmitry Belyavskiy <beldmit@gmail.com>
Reviewed-by: Paul Dale <pauli@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/19876)