Fix PostgreSQL migration bugs

[ehaldane-digicatapult]

Pull Request

Checklist

• Have you read Digital Catapult's Code of Conduct?
• I have performed a self-review of my own code.
• I have commented my code, particularly in hard-to-understand areas.
• I have made corresponding changes to the documentation.
• My changes generate no new warnings.
• I have added tests that prove my fix is effective or that my feature works.
• New and existing unit tests pass locally with my changes.

PR Type

Please delete options that are irrelevant.

• Bug Fix

Linked tickets

VR-548

High level description

CNPG clusters for the Veritable Helm charts do not correctly point to the respective secrets that are being created with templates/secret-cnpg-superuser.yaml. Instead, that reference needs to be explicit within the cnpg.cluster.initdb.secret.name field.

Another issue, specific to the UI, is that it will clobber the CNPG cluster, where both Helm charts attempt to use the same name. Here, the solution is to override one of the two, e.g. cloudagent.cnpg.fullnameOverride and then ensure that it matches its own respective secret for the cluster.