Add suspend and wakeup commands

[Nerox9]

Description

Suspend and wake-up commands are added into admin server with systemctl targets.

Checklist

• Summary of the proposed changes in the PR description
• More detailed description in the commit message(s)
• Commits are squashed into relevant entities - avoid a lot of minimal dev time commits in the PR
• Contribution guidelines followed
• Test procedure added to nixos/tests
• Author has run nix flake check --accept-flake-config and it passes
• All automatic Github Action checks pass - see actions
• Author has added reviewers and removed PR draft status

Testing

Run the command on guivm grpcurl -plaintext 192.168.101.10:9000 admin.AdminService.Suspend.
Observe the turned off display.
Interact with any key and observe the display turned on back.

[slakkala]

LGTM so far.

[vunnyso]

Does this PR replicate same behavior of doing system suspend from ghaf-host ?
If yes, unfortunately our gui-vm cannot suspend because virtio fs doesn't support suspend as of now with 6.10.2 kernel. We can turn off display of gui-vm as mentioned here to have better battery life.

[Nerox9]

Does this PR replicate same behavior of doing system suspend from ghaf-host ? If yes, unfortunately our gui-vm cannot suspend because virtio fs doesn't support suspend as of now with 6.10.2 kernel. We can turn off display of gui-vm as mentioned here to have better battery life.

Right, but we need to trigger it from GUI VM over GIVC too. Basically naming is just for the future implementation otherwise it uses the implementation you mentioned for now.