Merge Protocol and ProtocolBehaviour (#2962)

* Pass the peerset config to ProtocolBehaviour

* Don't pass the protocol versions

* Move fields from protocol_behaviour.rs to protocol.rs

* Remove LocalNetworkOut

* Move CustomProtos from protocol_behaviour.rs to protocol.rs

* Remove ProtocolBehaviour

* Inline poll()

* Force Behaviour to use Protocol

* Don't even attempt to have working tests

* Remove NetworkOut trait

* Line widths