Sans I/O and Forwarding separation

Currently [kira-lib] mixes I/O implementation (interface monitoring, message sending, (de)serialization) with the protocol implementation of R²/KAD and the fast-forwarding layer. The I/O orchestration of the routing-protocol R²/KAD and the fast forwarding layers should be moved into dedicated packages (kirad, kira-forwarding). Also, the protocol implementation of R²/KAD should be time agnostic to allow easier testing and integration in discrete event simulations like the RoutingSim.