UI: add test that finds out WAN address and checks if port is reachable from outside

[TriplEight]

Describe the bug

The server is now reachable at $address suggests the address that is not correct.
I've set up the port forwarding on the router and was wondering why it works in the local network and doesn't work via the external address. Just checked my real external address with anything like https://www.hashemian.com/whoami/ and connected via that address right away.

Also, must say that if I add a VPN connection, this external address is not changed as well, but in this case, I have to restart the app to connect to it.

It would be awesome if there was actually a test that finds out an external address and checks if it's reachable with a $port.

To Reproduce

1. Start
2. Check the connection string
3. External address != my public address (dynamic or not)

Expected Behavior

External address is correct and tested for availability, together with port

Logs/Backtraces

Your environment (please complete the following information):

• OS and version: 12
• VNC viewer and version: 1.2.3

Additional context

[bk138]

Well the UI only shows Local Area Network Addresses aka LAN. It does not show your WAN address. Turning this into a feature request.