Add block number to activated leaves and associated fixes (#2718)

* add number to `ActivatedLeavesUpdate`

* update subsystem util and overseer

* use new ActivatedLeaf everywhere

* sort view

* sorted and limited view in network bridge

* use live block hash only if it's newer

* grumples

polkadot/node/core/approval-voting/src/lib.rs

@@ -591,7 +591,8 @@ async fn handle_from_overseer(
 		FromOverseer::Signal(OverseerSignal::ActiveLeaves(update)) => {
 			let mut actions = Vec::new();
 
-			for (head, _span) in update.activated {
+			for activated in update.activated {
+				let head = activated.hash;
 				match import::handle_new_head(
 					ctx,
 					state,