#2 OZG-7121 helm: Add server certificate resource

src/main/helm/templates/_helpers.tpl

src/main/helm/templates/certificate.yaml

src/main/helm/templates/default_secret.yaml

src/main/helm/templates/selfsigned_cluster_issuer.yaml

src/main/helm/test-values.yaml

src/test/helm/certificate_test.yaml

src/test/helm/deployment_defaults_labels_test.yaml

src/test/helm/deployment_test.yaml

src/test/helm/service_monitor_test.yaml

src/test/helm/service_test.yaml