* Implement ProtocolsHandler methods in wrappers.
This PR forwards calls to some ProtocolsHandler methods that were
previously not implemented in wrappers such as `MapInEvent`.
It is unclear though how this can be implemented in some handlers
such as `MultiHandler` as the information at hand does not enable
it to decide which handler to forward the call to.
* Add `MultiHandler::inject_listen_ugrade_error`.
* Simplify trait bounds requirements
* More work
* Moar
* Finish
* Fix final tests
* More simplification
* Use separate traits for Inbound/Outbound
* Update gossipsub and remove warnings
* Add documentation to swarm
* Remove BoxSubstream
* Fix tests not compiling
* Fix stack overflow
* Address concerns
* For some reason my IDE ignored libp2p-kad