Add pruning to bechmarks & update weights. (#918)

* Insert headers in benchmarks.

* Fix benchmarks.

* Lower number of headers.

* Avoid hardcoding numbers.

* Update weights.

* cargo fmt --all

* Remove todo.

* Fix test.

* Address review comments.

* Fix borrowed value.

bridges/relays/bin-substrate/src/messages_lane.rs

@@ -203,7 +203,7 @@ mod tests {
 			// reserved for messages dispatch allows dispatch of non-trivial messages.
 			//
 			// Any significant change in this values should attract additional attention.
-			(1020, 216_583_333_334),
+			(1013, 216_583_333_334),
 		);
 	}
 }