Design and POC bookmarked VMs.

Goal

"Golden VMs" are VMs with customized VMs spec and disks. They could be called "templates" if the word wouldn't have already another meaning in OpenShift.
These golden VMs can be cloned to create new VMs, re-using the VM spec and the disk images.
The words "Golden VMs" or "Bookmarked VMs" or "Named Snaphots" all try to describe the same idea.

User Stories

• As a cluster admin, I would like to prepare "golden" custom VMs in restricted namespace, so that my users can create similar ones (clone? them) into their namespace and benefit from my preparation of the VMs in the future.

• As a developer, I would like to have and keep a VM in my namespace, so that I can use this as the base to create similar new VMs in the future.

Non-Requirements

• The preparation of the disk image itself (sysprep and generalize) is addressed in other epics.
• If only the disk images, but not the VM spec customization is required, the "Create VM from Volume" based on preferences and instancetypes is already sufficient.

Notes

• Should the bookmarked VMs prevented to be run?
• How can the flow be represented in web UI and CLI?

Done Checklist