P2P listener only works for incoming direct peer connections

[lumaaaaaa]

Additional work needs to be done to make the P2P listener more versatile, it should be able to accept different ConnectionTypes (P, F, D) and also support outgoing indirect connections (parsing PierceFirewall).

Also to fix the immediate issues caused by the P2P listening assuming that every incoming connection is a direct peer connection, proper control-flow branches should be added with appropriate stubs. Will also provide a nice scaffold for working on this.

[lumaaaaaa]

Scaffolded and stubbed, c9025dd

Implementation comes next