* update libp2p to 0.52.0

* proto name now must implement `AsRef<str>`

* update libp2p version everywhere

* ToSwarm, FromBehaviour, ToBehaviour

also LocalProtocolsChange and RemoteProtocolsChange

* new NetworkBehaviour invariants

* replace `Vec<u8>` with `StreamProtocol`

* rename ConnectionHandlerEvent::Custom to NotifyBehaviour

* remove DialError & ListenError invariants

also fix pending_events

* use connection_limits::Behaviour

See https://github.com/libp2p/rust-libp2p/pull/3885

* impl `void::Void` for `BehaviourOut`

also use `Behaviour::with_codec`

* KademliaHandler no longer public

* fix StreamProtocol construction

* update libp2p-identify to 0.2.0

* remove non-existing methods from PollParameters

rename ConnectionHandlerUpgrErr to StreamUpgradeError

* `P2p` now contains `PeerId`, not `Multihash`

* use multihash-codetable crate

* update Cargo.lock

* reformat text

* comment out tests for now

* remove `.into()` from P2p

* confirm observed addr manually

See https://github.com/libp2p/rust-libp2p/blob/master/protocols/identify/CHANGELOG.md#0430

* remove SwarmEvent::Banned

since we're not using `ban_peer_id`, this can be safely removed.
we may want to introduce `libp2p::allow_block_list` module in the future.

* fix imports

* replace `libp2p` with smaller deps in network-gossip

* bring back tests

* finish rewriting tests

* uncomment handler tests

* Revert "uncomment handler tests"

This reverts commit 720a06815887f4e10767c62b58864a7ec3a48e50.

* add a fixme

* update Cargo.lock

* remove extra From

* make void uninhabited

* fix discovery test

* use autonat protocols

confirming external addresses manually is unsafe in open networks

* fix SyncNotificationsClogged invariant

* only set server mode manually in tests

doubt that we need to set it on node since we're adding public addresses

* address @dmitry-markin comments

* remove autonat

* removed unused var

* fix EOL

* update smallvec and sha2

in attempt to compile polkadot

* bump k256

in attempt to build cumulus

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Co-authored-by: parity-processbot <>