fix(AdminSettings): test Websocket connection

[Antreesy]

☑️ Resolves

Allows to test websocket connection with HPB in Admin settings (before users will face it in Talk interface): client attempts to establish new websocket, then:

• clean close on success
• throw error if any

This can (for now) identify by close code a self-signed certificate net::ERR_CERT_AUTHORITY_INVALID, if blocked by browser. To test (if possible), need to revoke certificate for HPB address.

🖌️ UI Checklist

🖼️ Screenshots / Screencasts

🏚️ Before	🏡 After
None

🚧 Tasks

• Handle NC <-> HPB servers time sync issue
• Handle other cases that could be checked?

🏁 Checklist

• 🌏 Tested with different browsers / clients:
  • Chromium (Chrome / Edge / Opera / Brave)
  • Firefox
  • Safari
  • Talk Desktop
  • Not risky to browser differences / client

[Antreesy]

I'm lacking knowledge on how else this connection could fail (and how to reproduce it), so wouldn't mind a second opinion here
cc @danxuliu @fancycode @SystemKeeper

[fancycode]

Another thing you could test here is sending a hello request after the connection was established. This will verify that the backend url and shared secret are correctly configured in the signaling server.

[fancycode]

Regarding testing: this will also fail if the signaling server url is incorrect and the request can't be upgraded to a WebSocket. This can be seen in the response (could be 404 for unknown urls or something like 400 for valid urls that don't support WebSocket), but I'm not sure if you get all the details from the JavaScript API.