fix(ext/websocket): don't throw exception when sending to closed socket

[bellinitte]

The WebSocket specification for the send function says:

The browser will throw an exception if you call send() when the connection is in the CONNECTING state. If you call send() when the connection is in the CLOSING or CLOSED states, the browser will silently discard the data.

and:

Exceptions

InvalidStateError DOMException

Thrown if WebSocket.readyState is CONNECTING.

This pull request fixes the current behavior to match the specification. Also, I believe it fixes #17586.

[CLAassistant]

All committers have signed the CLA.

[littledivy]

LGTM