Websockets OnClose doesn't contain the close message

[Esildor]

When a websocket closes, they contain a reason for close, additionally they contain a message. Currently this libraries OnClose delegate just emits the reason enum and not a message too.

[j1mmie]

It also does not support sending back user-defined status codes during the closing handshake. Instead, NativeWebSocket passes an undefined WebSocketCloseCode to the event listener :(

More about user-defined status codes here: https://www.rfc-editor.org/rfc/rfc6455#section-7.4.2