Log raw WS messages to facilitate the debugging

[MOZGIII]

No description provided.

[mattsse]

I'm okay with logging these without a new feature

[MOZGIII]

I'd like to be able to turn these off though, as it's an extra copy on every message; would you consider keeping a feature but making it on by default? That way I can turn it off when needed.

I'm kind of interested in tuning performance here, as we could have a quite overhead-sensitive setup (proper measurements to confirm this are pending).

[ryo33]

I'd like to be able to turn these off though, as it's an extra copy on every message; would you consider keeping a feature but making it on by default? That way I can turn it off when needed.

Extra cloning can be avoided by this statement.

let msg_for_debug = if tracing::enabled!(target: "chromiumoxide::conn::raw_ws::parse_errors", tracing::Level::DEBUG) {
    Some(msg.clone)
} else {
    None
};

[ryo33]

I forked this branch and opened #204.
It's zero-copy.