Update VC and BN APIs for naive aggregation (#950)

* Refactor `Attestation` production

* Add constant

* Start refactor for aggregation

* Return early when no attesting validators

* Refactor into individual functions

* Tidy, add comments

* Add first draft of NaiveAggregationPool

* Further progress on naive aggregation pool

* Fix compile errors in VC

* Change locking logic for naive pool

* Introduce AttesationType

* Add pruning, comments

* Add MAX_ATTESTATIONS_PER_SLOT restriction

* Add pruning based on slot

* Update BN for new aggregation fns

* Fix test compile errors

* Fix failing rest_api test

* Move SignedAggregateAndProof into own file

* Update docs, fix warning

* Tidy some formatting in validator API

* Remove T::default_spec from signing

* Fix failing rest test

* Tidy

* Add test, fix bug

* Improve naive pool tests

* Add max attestations test

* Revert changes to the op_pool

* Refactor timer

beacon_node/beacon_chain/src/test_utils.rs

@@ -6,7 +6,7 @@ use crate::{
     builder::{BeaconChainBuilder, Witness},
     eth1_chain::CachingEth1Backend,
     events::NullEventHandler,
-    AttestationProcessingOutcome, BeaconChain, BeaconChainTypes, StateSkipConfig,
+    AttestationProcessingOutcome, AttestationType, BeaconChain, BeaconChainTypes, StateSkipConfig,
 };
 use genesis::interop_genesis_state;
 use rayon::prelude::*;
@@ -342,7 +342,7 @@ where
         .for_each(|attestation| {
             match self
                 .chain
-                .process_attestation(attestation, Some(false))
+                .process_attestation(attestation, AttestationType::Aggregated)
                 .expect("should not error during attestation processing")
             {
                 AttestationProcessingOutcome::Processed => (),