[WebSocket Sync Client] Add Cookie support

[Bhashinee]

$subject.

http:Cookie cookie = new ("username", "name");
http:Cookie[] httpCookies = [cookie];

websocket:ClientConfiguration clientConf = {
   cookies: httpCookies
};

websocket:Client wsClient = check new("ws://localhost:21316/testCookieSync/", config = clientConf);