Better error messages in case of node unavailability

[isezen]

Right now, bazuka node status returns the following output if node is not running:

thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: ServerError(hyper::Error(Connect, ConnectError("tcp connect error", Os { code: 111, kind: ConnectionRefused, message: "Connection refused" })))', src/main.rs:371:18
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

Instead, it is better to inform user with a message Node Stopped or Node is not running.