OSSL_STORE and PKCS#12: Check if there is a MAC to verify before prompting

OSSL_STORE and PKCS#12: Check if there is a MAC to verify before prompting

When a DER object with unknown contents comes all the way to
ossl_store_handle_load_result(), and it attempts to decode them as different
objects, the PKCS#12 decoding attempt would (almost) always prompt for a
passphrase, even if there isn't a MAC to verify it against in the PKCS#12
object.

This change checks if there is a MAC to verify against before attempting to
prompt for a passphrase, leading to less surprising behavior.

Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Dmitry Belyavskiy <beldmit@gmail.com>
Reviewed-by: Paul Dale <pauli@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/21197)