public static void toSlime(List<X509Certificate> certificateList, Cursor array) {
        certificateList.stream()
                .map(X509CertificateUtils::toPem)
                .forEach(array::addString);
    }
Serializer for operator certificates.
The certificates are serialized as a list of PEM strings.
@author tokle
configserver/src/main/java/com/yahoo/vespa/config/server/tenant/OperatorCertificateSerializer.java