[fips] Nats - use test-support-certificate-generator

[JiriOndrusek]

Describe the feature here

When I sed certificate-generator:

@TestCertificates(certificates = {
        @Certificate(name = "nats", formats = {
                Format.PKCS12, Format.PEM }, password = "password")
}, baseDir = "target/classes/ssl")

I got an error with non-existent algorithm on FIPS machine (in JVM) - has to be investigated.