More Test Cases for Live Migration (AMX, negative tests, cancellation)

More test cases:

- [ ] AMX
- [ ] live migration + libvirt domain shutdown
- [ ] live migration + libvirt daemon restart during live migration
- [ ] live migration cancellation
- [ ] virsh: start live migration when a live migration is ongoing
- [ ] live migration with tls + sender/receiver VMM kill
- [ ] live migration + cpu profiles + hotplug CPU on new machine 