Add ability to clone a container from the GUI

Problem/Justification
Saves time to config a container once it is created

Impact
we had this in v25 from the CLI. Now it isn’t there.

User Story
Create container. Customize it with users, setting, installed apps. Now snapshot it as “gold”.

You should be able to make a new container from “gold.”

You can zfs clone the snapshot, but the GUI does NOT pick up that the new clone exists.