[feature request] Allow ObjectStore config to use endpointCA from ConfigMap in addition to Secret

[poehlerflorian]

Currently, the ObjectStore config only allows specifying the CA certificates from a secret. We are using trust manager to distribute the certificates as config maps. The BarmanObjectStoreConfiguration however only allows secrets to be specified.

e.g.:

apiVersion: barmancloud.cnpg.io/v1
kind: ObjectStore
metadata:
  name: my-obj-store
spec:
  configuration:
    endpointURL: https://<s3-endpoint-url>
    endpointCA:
      configMapRef:
        name: my-ca-configmap
        key: ca.crt