Implement TRY_DAKEZ_WHEN_OFFLINE policy
Created by: olabini
When it looks like the peer is offline, the default behavior will be to start a non-interactive auth instead of an interactive one. However, because not all networks will be able to reliably tell you if the other party is offline, and people can be invisible etc, it might be worth sending an interactive DAKE as well, so that the other party can use the stronger DAKE if possible. If this policy is turned on, that will happen - otherwise only the non-interactive will happen.
This should be possible to configure in the UI.
(We might need another policy to govern whether we should respond to a DAKEZ when we are invisible.)