listener.isOpen() returns always false

[xembook]

https://github.com/nemtech/symbol-sdk-typescript-javascript/blob/2b18ca2f991aa692dd4384e93b7377954faed695/src/infrastructure/Listener.ts#L200

I want to use listener.isOpen() on browser WebSocket, but it returns always false.
because WebSocket.OPEN is always undefined.

I think it should be corrected as follows.

return this.webSocket.readyState === this.webSocket.OPEN;

please check this, thank you.

[xembook]

Please check if other places are behaving as expected.

https://github.com/nemtech/symbol-sdk-typescript-javascript/blob/2b18ca2f991aa692dd4384e93b7377954faed695/src/infrastructure/Listener.ts#L103

https://github.com/nemtech/symbol-sdk-typescript-javascript/blob/2b18ca2f991aa692dd4384e93b7377954faed695/src/infrastructure/Listener.ts#L210

[rg911]

@xembook good catch. it is a bug on injected ws listener. 👍