Implement a test for PAC_TYPE_CREDENTIAL_INFO (PKINIT) to check that the blob we add is valid.
This bug was referenced in samba master: 97ead77767c7a30e61c9916d478203041cde89d7
This bug was referenced in samba v4-19-test: 97ead77767c7a30e61c9916d478203041cde89d7
This bug was referenced in samba v4-19-stable (Release samba-4.19.0rc1): 97ead77767c7a30e61c9916d478203041cde89d7