Expose the Helm managed resource list for the frontend without giving access to the underlying secret

We allow visualising a tree view starting with a Kustomization resource. To add support for HelmRelease, we need a list of resources managed by the specific Helm release. Helm stores the resource list in a secret.

Users (especially impersonated users) likely won't have RBAC to read the Helm secrets.

Proposal

Read the Helm secret with the go backend, and expose the resource list as an API for the frontend to render the direct child of the HelmRelease.

Implementation notes

There are two storage backends:

• https://github.com/helm/helm/blob/main/pkg/storage/driver/cfgmaps.go
• https://github.com/helm/helm/blob/main/pkg/storage/driver/secrets.go