Simplify trait bounds in network to prepare for collator-rpc (#12082)

* Hack towards PoC

* Abstract away runtime requirement

* blockchainevents

* Remove bitswap

* Remove unused sync more

* Remove unused features in network

* Re-enable bitswap change

* Remove `Chain` trait bound

* Reimplement blockchain-rpc-events

* Move network to cumulus

* Make AuthorityDiscovery async

* Remove `ProofProvider` requirement from network behaviour

* Extract bitswap

* Adjustments after merge

* Remove HeaderMetadata trait from network

* Introduce NetworkHeaderBackend

* Add comments

* Improve comments

* Move NetworkHeaderBackend to new module

* Improve naming, remove redundand send + sync

* Clean up generics

* Fix CI

* Improve comment and readability

* Remove NetworkHeaderBackend

* Fix Cargo.lock

Co-authored-by: Sebastian Kunert <skunert@Sebastians-MacBook-Pro.fritz.box>

substrate/client/network/src/config.rs

@@ -31,7 +31,7 @@ pub use sc_network_common::{
 
 pub use libp2p::{build_multiaddr, core::PublicKey, identity};
 
-use crate::ExHashT;
+use crate::{bitswap::Bitswap, ExHashT};
 
 use core::{fmt, iter};
 use futures::future;
@@ -80,6 +80,9 @@ where
 	/// Client that contains the blockchain.
 	pub chain: Arc<Client>,
 
+	/// Bitswap block request protocol implementation.
+	pub bitswap: Option<Bitswap<B>>,
+
 	/// Pool of transactions.
 	///
 	/// The network worker will fetch transactions from this object in order to propagate them on