Validate base image with controller

[berndtj]

Feature Request

Detailed Description

Currently base images are managed with simply a CRD. There is no controller attached to it which can validate the validity of the base image. This should be added.

Context

Possible Implementation

Complexity

• Low - Simple enhancement or bug fix, no architectural changes or refactoring
• Medium - Change requires some thought, but is relatively isolated
• High - Significant architectural change or large refactor