Allow default routing & exit nodes via Pangolin app

[SystemFuchs]

Summary

Route all traffic through Pangolin & allow to choose an exit node

Motivation

It can be desirable to route all traffic from e.g. a mobile client (laptop or phone) through a Pangolin tunnel and let traffic exit at another node.

Proposed Solution

A switch inside the app where the user can choose

a) usage of exit node
b) choose an defined exit node

Alternatives Considered

No response

Additional Context

No response

[kingtutbvi]

They taking long with this feature lol