put the security protocol in multiaddrs

[marten-seemann]

Corresponding spec change:

• addressing: Specify security protocols in multiaddr specs#353

PRs (list WIP):

• change interfaces for the security-in-multiaddr change go-libp2p-core#215
• make it possible to skip the handshake negotiation go-libp2p-transport-upgrader#87
• use the changed Transport.Protocols method go-libp2p-testing#39
• make it possible to listen on and dial security-enabled multiaddrs go-tcp-transport#98
• implement the Protocol method on the Transport go-libp2p-tls#95
• implement the Protocol method on the Transport go-libp2p-noise#105
• update the signature of the Protocols method go-libp2p-quic-transport#232
• update the signature of the Protocols method go-ws-transport#107
• update the signature of the Protocols method go-libp2p-circuit#142
• listen on and dial security-enabled multiaddrs go-libp2p-swarm#285
• construct a separate transport for every handshake protocol #1195

[marten-seemann]

Updating priority to P3. We probably won't tackle this issue any time soon.