openssl_certificate: Return self.cert.get_VALUES() (#33970)

Currently when we make up the return value, we take values based of the
parameters rather than the generated openssl_certificate itself.

This commits returns the actual certificate values making it all time
accurate.

test/integration/targets/openssl_certificate/tests/validate.yml

@@ -16,6 +16,13 @@
       - cert_modulus.stdout == privatekey_modulus.stdout
       - cert_version.stdout == '3'
 
+- name: Validate certificate idempotence
+  assert:
+    that:
+      - selfsigned_certificate.serial_number == selfsigned_certificate_idempotence.serial_number
+      - selfsigned_certificate.notBefore == selfsigned_certificate_idempotence.notBefore
+      - selfsigned_certificate.notAfter == selfsigned_certificate_idempotence.notAfter
+
 - name: Validate certificate v2 (test - certificate version == 2)
   shell: 'openssl x509 -noout  -in {{ output_dir}}/cert_v2.pem -text | grep "Version" | sed "s/.*: \(.*\) .*/\1/g"'
   register: cert_v2_version