[epic] ClusterExtension Controller embeds helm for managing installed content

[joelanford]

Brief

Tasks

• [ ] #610

[varshaprasad96]

Brief up for review: https://docs.google.com/document/d/1GvmHQxjwCOS6xEZqWTCf5UoQB3DzdSMKIKfJZLiG3X0/edit#heading=h.btd8kkom5km4

[itroyano]

Hi, 2.5 cents

The engine for applying a helm chart already exists in the helm-operator-plugin code, so the two main feats here in my opinion are:

1. Define a generic and "friendly" structure for a bundle that represents a Helm chart, and customizable values for its installation. The values part is key. it needs to have good & clear UX, and there needs to be an option for the bundle to provide a validation schema and/or webhooks, such that invalid input can be rejected before running the actual engine.

2. Convert the bundle to something the existing helm engine understands. a temporary CR that goes into the Unstructured parser code for example, or some other impl.

[tmshort]

This is done now.