[Bug] CommonName field in certificates may be too long

[ebaron]

There's a requirement that the spec.CommonName field of certificates be at most 64 characters. We should change our certificates to use constant short values for common name:

2024-10-22T20:17:49Z ERROR Reconciler error {"controller": "cryostat", "controllerGroup": "operator.cryostat.io", "controllerKind": "Cryostat", "Cryostat": {"name":"cryostat-sample","namespace":"cryostat-operator-system"}, "namespace": "cryostat-operator-system", "name": "cryostat-sample", "reconcileID": "c9d0f0c3-6727-4d81-8d77-df7fe3978012", "error": "admission webhook \"webhook.cert-manager.io\" denied the request: spec.commonName: Too long: must have at most 64 bytes"}

Each certificate already uses DNSNames, which override CommonName for hostname verification.