Create kbs certificates and private key

[alicefr]

The certificate generation for the KBS is currently missing. Trustee doesn't currently support cert-manager, but it will be handy to integrate the certificate generation and add it to the operator.
Something like this:

apiVersion: cert-manager.io/v1
kind: Issuer
metadata:
  name: kbs-https
  namespace: operators
spec:
  selfSigned: {}
---
apiVersion: cert-manager.io/v1
kind: Certificate
metadata:
  name: kbs-https
  namespace: operators
spec:
  dnsNames:
    - kbs.operators.svc
  secretName: kbs-https-certificate
  issuerRef:
    name: kbs-https