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

hostd/src/machine.rs

@@ -34,7 +34,7 @@ pub async fn describe(
         // convert bytes to hex string
         .iter()
         .map(|&b| format!("{:02x}", b))
-        .collect::<String>();
+        .collect();
 
     let machine_info = MachineInfo { machine_id };