Remove the guts of the OBJ_NAME API

Remove the guts of the OBJ_NAME API

With one exception, none of this is used anymore. All of it will be removed
in the next major bump.

The exception is OBJ_NAME_add(). scurity/xca ran into issues with their
cert renewal logic because RSA certs had a way of mapping the signature
algorithms to a hash, but a similar mechanism wasn't available for ECDSA
certs. So xca uses EVP_add_digest_alias() to have corresponding aliases
for ECDSA. This is a macro wrapping OBJ_NAME_add().

xca now has better logic using the more appropriate OBJ_find_sigid_algs()
(which wasn't available back then). We will still add the alias entries
that xca still adds ourselves to make sure there are no unexpected side
effects. They make sense anyway.

The diff will hopefully land in a few days. If your life depends on ECDSA
cert renewal in xca please hold off on updating to a new snap.

ok jsing