Handle WireGuard tunnel disconnection for MFA on iOS.

[moubctez]

Find a way to notify iOS app that the network extension is unable to make a tunnel to the endpoint.

• Send notifications from the network extension to the application.
• Network extension should be aware if the connection is broken and disable itself (is possible).
• Application should inform the user that the connection is broken via a toast

[teon]

@t-aleksander current test:

Worked for 1h. Then server disconnected. But mobile app didn't detect that and my internet did not work (showing that I'm connected to VPN).