Check whether LE certificates are APPROVED in GKE-LETSENCRYPT-CI test

[thehejik]

We should at least add parsing of output from this command:

$ k get certificaterequests.cert-manager.io -A
NAMESPACE      NAME                                                                APPROVED   DENIED   READY   ISSUER                REQUESTOR                                         AGE
cert-manager   epinio-ca-1                                                         True                True    selfsigned-issuer     system:serviceaccount:cert-manager:cert-manager   23m
epinio         dex-tls-1                                                           True                True    letsencrypt-staging   system:serviceaccount:cert-manager:cert-manager   23m
epinio         epinio-1                                                            True                True    letsencrypt-staging   system:serviceaccount:cert-manager:cert-manager   23m
epinio         epinio-registry-1                                                   True                True    epinio-ca             system:serviceaccount:cert-manager:cert-manager   23m
epinio         minio-cert-1                                                        True                True    epinio-ca             system:serviceaccount:cert-manager:cert-manager   23m
workspace      rsample-sampleid23421--ceac60559b0996dd420c618e84e0a1bdc48874d6-1   True                True    letsencrypt-staging   system:serviceaccount:cert-manager:cert-manager   18m

And check if the correct ISSUER was used and if the CSR is APPROVED for epinio, dex and workload resources.
It can be extended in Scenario2 file https://github.com/epinio/epinio/blob/main/acceptance/install/scenario2_test.go#L199