ps: Mark VM with * when the state can't be confirmed

[darkowlzz]

While listing the VMs, if the latest status of the VMs can't be
confirmed due to a runtime engine error, the status can't be confirmed.
Mark such VMs with the * symbol to indicate potentially outdated status.

VM ID                   IMAGE                           KERNEL                                  SIZE    CPUS    MEMORY          CREATED         STATUS          IPS         PORTS   NAME
77e0d9469b154da3        weaveworks/ignite-ubuntu:latest weaveworks/ignite-kernel:4.19.125       4.0 GB  1       512.0 MB        55m ago         Up 55m          10.61.0.2           my-vm
7e6c9464555b2513        weaveworks/ignite-ubuntu:latest weaveworks/ignite-kernel:4.19.125       4.0 GB  1       512.0 MB        4m19s ago       *Up 4m19s       172.17.0.2          my-vm2
WARN[0000] The symbol * on the VM status indicates that the VM manifest on disk may not be up-to-date with the actual VM status from the container runtime
WARN[0000] failed to inspect container for VM e52958f1852002e002a5a1d01c40a13d59ea6d13fbe6a5ecd4d61834a42a62b1: Error: No such container: e52958f1852002e002a5a1d01c40a13d59ea6d13fbe6a5ecd4d61834a42a62b1

[stealthybox]

LGTM -- nice catch :)