Upgrade to libp2p 0.51.3 (#13587)

* client/network: upgrade to libp2p 0.51.0

* make discovery.rs compile

* make peer_info.rs compile

* changes to notifications and request-response proto

* make service.rs compile

* towards making request_responses.rs compile

* make request_responses.rs compile

* make request_responses.rs compile

* fix notifications/behaviour.rs tests

* fix warnings

* remove old code

* allow deprecated code (temporary)

* upgrade to libp2p 0.51.1

* add TODO for behaviour tests

* return empty vec if peer_id is absent

https://github.com/paritytech/substrate/pull/13587#discussion_r1141695167

fyi: I don't really know what the old behaviour was.

* update comment to reflect new defaults

Closes #13338

* Revert "update comment to reflect new defaults"

This reverts commit 7a981abd69308e9d522ec94905f181439a1b1dba.

* remove config.rs (from wrong merge)

* upgrade to libp2p 0.51.2

* fix formatting

* use handle_pending_outbound_connection in networt_state RPC

* update deps

* use re-exports when we use other libp2p packages

* Apply suggestions from code review

Co-authored-by: Dmitry Markin <dmitry@markin.tech>

* format code

* handle potential errors in network_state RPC

* only update libp2p crate

* update libp2p-core

* fix docs

* use libp2p-identity instead of libp2p

where it's possible. libp2p-identity is much smaller, hence makes sense
to use it instead of larger libp2p crate.

* Update client/network/src/discovery.rs

Co-authored-by: Aaro Altonen <48052676+altonen@users.noreply.github.com>

* update Cargo.lock

* add comment for per_connection_event_buffer_size

current value is somewhat arbitrary and needs to be tweaked depending on
memory usage and network worker sleep stats.

* fix link format

* update Cargo.lock

* upgrade to libp2p 0.51.3

* deprecate mplex

* Revert "deprecate mplex"

This reverts commit 9e25820e706e464a0e962a8604861fcb2a7641eb.

* Revert "upgrade to libp2p 0.51.3"

This reverts commit 6544dd4138e2f89517bd7c7281fc78a638ec7040.

* use new libp2p version in `statement` crate

* pin version temporarily

* libp2p 0.51.3

* deprecate mplex

* deprecate legacy noise handshake

* fix build error

* update libp2p-identity

* enable libp2p-identity:ed25519 feature in sc-consensus

* enable ed25519 for peerset as well

---------

Co-authored-by: Dmitry Markin <dmitry@markin.tech>
Co-authored-by: Aaro Altonen <48052676+altonen@users.noreply.github.com>
Co-authored-by: parity-processbot <>