Storage chains: serve transactions over IPFS/bitswap (#7963)

* IPFS server for transactions

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Co-authored-by: Pierre Krieger <pierre.krieger1708@gmail.com>

* Style

* Style

* Minor fixes

Co-authored-by: Pierre Krieger <pierre.krieger1708@gmail.com>

substrate/client/network/src/config.rs

@@ -420,6 +420,8 @@ pub struct NetworkConfiguration {
 	/// Require iterative Kademlia DHT queries to use disjoint paths for increased resiliency in
 	/// the presence of potentially adversarial nodes.
 	pub kademlia_disjoint_query_paths: bool,
+	/// Enable serving block data over IPFS bitswap.
+	pub ipfs_server: bool,
 
 	/// Size of Yamux receive window of all substreams. `None` for the default (256kiB).
 	/// Any value less than 256kiB is invalid.
@@ -472,6 +474,7 @@ impl NetworkConfiguration {
 			allow_non_globals_in_dht: false,
 			kademlia_disjoint_query_paths: false,
 			yamux_window_size: None,
+			ipfs_server: false,
 		}
 	}