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

eth2/state_processing/src/per_block_processing/errors.rs

@@ -1,4 +1,5 @@
 use super::signature_sets::Error as SignatureSetError;
+use merkle_proof::MerkleTreeError;
 use types::*;
 
 /// The error returned from the `per_block_processing` function. Indicates that a block is either
@@ -46,6 +47,7 @@ pub enum BlockProcessingError {
     BeaconStateError(BeaconStateError),
     SignatureSetError(SignatureSetError),
     SszTypesError(ssz_types::Error),
+    MerkleTreeError(MerkleTreeError),
 }
 
 impl From<BeaconStateError> for BlockProcessingError {