Support for disk expansion without having to reboot the vm, and support for adding a disk to the vm during its lifetime

[simonebenati]

Is your feature request related to a problem? Please describe.
I would like to avoid to recreate each time the vm if I want to add a disk block, or I would like to not reboot the vm if I decide to resize the disk size

Describe the solution you'd like
Add a disk to the VM without recreating the instance (if possible) and avoid rebooting the VM when resizing a disk

Describe alternatives you've considered

Additional context

[simonebenati]

Also please if, possible make it so that when adding a disk while starting the machine from a clone it works correctly in that scenario without having to recreate the cloned machine

[bpg]

Also in #103