Allow System owners to add sub-owners (RBAC)

Hi there,

We were expirimenting with adding multiple system owners to a single/multiple virtual systems. As super administraotrs, this is no issue. However, when we switch to the owners account, we do not have an option for "Virtual System Owners". Virtualmin has a similar feature and you can add multiple users and give them specific controls over a website. It looks like sub-user support for Cloudmin is there already, maybe we are just missing something? We checked the permissions in plans and the Cloudmin configuration but could not find anything. Looking forward to hearing back, thank you!