Force hard system shutdown instead of suspend/hibernate

[eloquence]

For security reasons (e.g., full-disk encryption state, application of automatic system updates, etc.), we should ensure that the system is shut down instead of suspended/hibernated. At minimum, this should occur when closing the laptop lid; if we can disable (at least at the UI level) suspend/hibernate altogether, that would be preferable.

[conorsch]

this should occur when closing the laptop lid

That we can do via /etc/systemd/logind.conf, setting HandleLidClose=poweroff (then bounce systemd-logind) in dom0. Tested it and it does indeed power off the machine when the lid is closed.

We'll need something else for disabling suspend altogether. A third case: when the machine is left idle for many hours, probably worth a shutdown, as well.

[eloquence]

That we can do via /etc/systemd/logind.conf, setting HandleLidClose=poweroff

Nit: the setting is named HandleLidSwitch. I can confirm that changing it to poweroff and running sudo systemctl restart systemd-logind alters the behavior on my X1 Carbon as expected.

[emkll]

Closed via #475 and #473