Refactor main loop in raft node thread for better readability

[hhwyt]

The loop symbol for the raft node threads is difficult to notice and can be easily overlooked:

        let handle = thread::spawn(move || loop {
            thread::sleep(Duration::from_millis(10));
            ...

For better readability, we should move the loop to the next line:

        let handle = thread::spawn(move || {
           loop {
                 thread::sleep(Duration::from_millis(10));
                 ...

[hhwyt]

/assign hhwyt