Optimizations, disable val client sync check & additional lcli tools (#834)

* Start adding interop genesis state to lcli

* Use more efficient method to generate genesis state

* Remove duplicate int_to_bytes32

* Add lcli command to change state genesis time

* Add option to allow VC to start with unsynced BN

* Set VC to do parallel key loading

* Don't default to dummy eth1 backend

* Add endpoint to dump operation pool

* Add metrics for op pool

* Remove state clone for slot notifier

* Add mem size approximation for tree hash cache

* Avoid cloning tree hash when getting head

* Fix failing API tests

* Address Michael's comments

* Add HashMap::from_par_iter

beacon_node/rest_api/src/router.rs

@@ -151,6 +151,9 @@ pub fn route<T: BeaconChainTypes>(
             (&Method::GET, "/advanced/fork_choice") => {
                 into_boxfut(advanced::get_fork_choice::<T>(req, beacon_chain))
             }
+            (&Method::GET, "/advanced/operation_pool") => {
+                into_boxfut(advanced::get_operation_pool::<T>(req, beacon_chain))
+            }
 
             (&Method::GET, "/metrics") => into_boxfut(metrics::get_prometheus::<T>(
                 req,