Add various OBJ functions as callbacks

Add various OBJ functions as callbacks

This enables providers to register new OIDs in the same libcrypto instance
as is used by the application.

Fixes #15624

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Paul Dale <pauli@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/15681)