feat(hostd): varlink interfaced host controller to manage machine configuration and boot mgmt

hostd/src/machine.rs

@@ -1,7 +1,7 @@
 use dropshot::{endpoint, HttpError, HttpResponseOk, RequestContext};
 use schemars::JsonSchema;
 use serde::Serialize;
-use std::sync::{Arc, Mutex};
+use std::sync::Arc;
 use trace_request::trace_request;
 
 use systemd_ipc::addrs::SYSTEMD_HOSTNAME;