UI: VM's on crashed node show as running

##### ISSUE TYPE

* Bug Report

##### COMPONENT NAME

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UI
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##### CLOUDSTACK VERSION

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4.18.1.0
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##### CONFIGURATION

N/A

##### OS / ENVIRONMENT

N/A

##### SUMMARY

When a kvm node crashes (no maintenance) the VM's running on that node will still show the status "Running" in the dashboard.
When accessing the VM itself you get the error message:
`The Control Plane Status of this instance is Offline. Some actions on this instance will fail, if so please wait a while and retry.`
When the kvm node restarts, after some time the VM's on it will show as "Stopped" and will have to be started manually.

##### STEPS TO REPRODUCE

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Force reboot without maintenance a kvm node that run's compute resources
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##### EXPECTED RESULTS

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I would expect the VM's to show as Stopped/Crashed as soon as the kvm node goes down
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##### ACTUAL RESULTS

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VM looks as running:
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VM details says there is an issue with control plane:
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Node is offline:
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Inizia nelle viste dashboard e dettagli VM, riproducendo il problema riavviando forzatamente un nodo KVM senza manutenzione. Traccia come lo stato offline del control plane viene riflesso nello stato della VM; il lavoro è completato quando le VM interessate mostrano prontamente Stopped o Crashed e rimangono coerenti dopo il riavvio del nodo.

Scritto dal modello di indicizzazione a partire dal testo della issue.