plugin-barman-cloud helm chart exposes value to set the name of the cert issuer, but doesnt actually use it when rendering the certificate resources.

I was trying to configure the helm chart to use my own cluster issuer instead of the self signed one. I saw in default values it exposes "issuerName" in the certificates block but currently its not used when templating the cert resources. It would be nice to make it possible to configure a custom issuer/clusterIssuer to use for the client/server certs.