In #31088 compression support in WebSocket was introduced. There was added WebSocketMessageFlags.DisableCompression flag which is needed to turn off compression i.e. when sending data containing secrets -- it helps to avoid CRIME/BREACH attacks.

However, this flag was added only in WebSocket and not in ClientWebSocket which is supposed to manage messages. We need to expose DisableCompression flag in SendAsync methods as well as it is done for EndOfMessage flag.