Event-based block lookup tests (#5534)

* WIP

* Initial working version of new sync tests.

* Remove sync traits and fix lints.

* Reduce internal method visibility and make test method instead. Remove extra beacon chain harness instance created in tests.

* Improve `SyncTester` api.

* Fix lint.

* Test example

* Lookup tests using rig

* Tests should interface with events only

* lint

* Skip deneb test pre-deneb

* Add more assertions

* Remove logging changes

* Address @jimmygchen comments

* Merge branch 'unstable' of https://github.com/sigp/lighthouse into bn-p2p-tests

* remove unused assertions

* fix lint

beacon_node/network/src/sync/range_sync/range.rs

@@ -637,7 +637,12 @@ mod tests {
         let (network_tx, network_rx) = mpsc::unbounded_channel();
         let globals = Arc::new(NetworkGlobals::new_test_globals(Vec::new(), &log));
         let (network_beacon_processor, beacon_processor_rx) =
-            NetworkBeaconProcessor::null_for_testing(globals.clone());
+            NetworkBeaconProcessor::null_for_testing(
+                globals.clone(),
+                chain.clone(),
+                harness.runtime.task_executor.clone(),
+                log.clone(),
+            );
         let cx = SyncNetworkContext::new(
             network_tx,
             Arc::new(network_beacon_processor),