Consider using minikube image ls

[medyagh]

consider if it worth using minikube image ls to list the images in a cluster

[medyagh]

cc: @aaron-prindle

[aaron-prindle]

In discussions offline, it seemed that this would involve modifying findKnownImages or loadImages here:
https://github.com/GoogleContainerTools/skaffold/blob/master/pkg/skaffold/runner/v1/load_images.go#L93

I took a WIP inital stab here but see that just using minikube image ls here will be unused code atm:
https://github.com/GoogleContainerTools/skaffold/pull/5956/files

I see now that loadImages is only called currently for kind and k3d when they use their respective "load" commands:

kind:
https://github.com/GoogleContainerTools/skaffold/blob/master/pkg/skaffold/runner/v1/load_images.go#L38

k3d:
https://github.com/GoogleContainerTools/skaffold/blob/master/pkg/skaffold/runner/v1/load_images.go#L46

Minikube does not use it's load command currently so using minikube image ls would be unused code atm. Should this PR include/go-after a PR to use minikube image load? Perhaps I am missing the utility/code-locations this could be used? Thanks.

[aaron-prindle]

Talked offline, this will go in after #5773 which @briandealwis is currently working on