Simplify Image Handling

[stevekuznetsov]

Right now there are two main causes of confusion and complexity around container images in the repo:

1. the multitude of ways in which container images may be specified, and their hierarchy
   a. annotating the HostedCluster
   b. providing flags to the hypershift-operator
   c. setting spec fields in the HostedCluster
   d. self-referential live lookups using the in-cluster client
2. the fact that the code believes there to be many component images (e.g. for the availability-prober, control-plane-operator, etc) when there is in fact just one

Ideally, we should determine if a) any production environment needs to support multiple component images and, if not, remove that concept as well as b) simplify the many avenues for determining what images are used, and when.

[openshift-bot]

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[openshift-bot]

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