Peer Store for each Polykey node #36
Description
we need to figure out how to layout our storage for peer information in order to keep track of things like which peers are connected, their accepted protocols/address etc. We can draw on inspiration from libp2p: https://github.com/libp2p/js-libp2p/tree/0.28.x/src/peer-store and hyperswarm: https://github.com/hyperswarm/hyperswarm
For now I think something simple and extensible is appropriate.