:lady_beetle: Bug: vm_boot_devices likely does not correctly reboot VM

[justinc1]

Describe the bug

Text from #287

# plugins/modules/vm_boot_devices.py
    if vm:
        # TODO BUG, this does not work - copy of `vm` is used in say ensure_present
        vm.vm_power_up(module, rest_client)

Check the comment, extend test, fix bug.