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/Cargo.toml

@@ -58,3 +58,4 @@ environment = { workspace = true }
 disable-backfill = []
 fork_from_env = ["beacon_chain/fork_from_env"]
 portable = ["beacon_chain/portable"]
+test_logger = []