Add WebSocket support for the iOS

Ktor Version and Engine Used (client or server and name) Using io.ktor:ktor-client-ios:1.3.2

Describe the bug This code prints kotlin.IllegalStateException: [generateNonce] is not supported on iOS:

  GlobalScope.launch {
    try {
      HttpClient {
        install(WebSockets)
      }.wss(
        host = "websocketstest.com",
        path = "/service"
      ) {
        send(Frame.Text("timer"))
        for (frame in incoming)
          println((frame as Frame.Text).readText())
      }
    } catch (e: Exception) {
      println(e)
    }
  }

Looks like someone tried to fix this here: https://github.com/ktorio/ktor/pull/1535

[AlexanderKudinov]

Hi! Any news? Websocket support for iOS (namely for KMM) is really very necessary. Looking forward!

[e5l]

Hi @Hixie, the WebSocket is unsupported on the iOS for now.