Pull through container registry cache for demo

[richardcase]

Describe the solution you'd like:
Currently, when provisioning a cluster the containers required are pulled down for every node which increases the provisioning time. It would be worth us using a container registry that support pull through caching. We can then configure containerd on the microvm nodes to use this registry as a cache.

It would be worth looking at:

• Harbor
• Docker Registry

We could also look at a HTTP proxy cache such as Envoy, HAProxy

Why do you want this feature:

To speed up provisioning of nodes.

Anything else you would like to add:
[Miscellaneous information that will assist in solving the issue.]

[github-actions]

This issue is stale because it has been open 60 days with no activity.