Allow reroot on ZFS from console and GUI reboot menu entries
Moving from internal Redmine 6304 since this affects CE and Plus and isn't hardware-dependent.
In current 21.02 snaps re-root works fine in ZFS.
This was prevented in the past because it led to a crash with ZFS, but that was 4 years and many versions ago:
Looks like that PR was fixed up long ago and so it should be safe now.
Done on CE:
And for Plus: