Misc changes for merge testnets (#2667)

* Thread eth1_block_hash into interop genesis state

* Add merge-fork-epoch flag

* Build LH with minimal spec by default

* Add verbose logs to execution_layer

* Add --http-allow-sync-stalled flag

* Update lcli new-testnet to create genesis state

* Fix http test

* Fix compile errors in tests

beacon_node/src/config.rs

@@ -131,6 +131,10 @@ pub fn get_config<E: EthSpec>(
         });
     }
 
+    if cli_args.is_present("http-allow-sync-stalled") {
+        client_config.http_api.allow_sync_stalled = true;
+    }
+
     /*
      * Prometheus metrics HTTP server
      */