Use E for EthSpec globally (#5264)

* Use `E` for `EthSpec` globally

* Fix tests

* Merge branch 'unstable' into e-ethspec

* Merge branch 'unstable' into e-ethspec

# Conflicts:
#	beacon_node/execution_layer/src/engine_api.rs
#	beacon_node/execution_layer/src/engine_api/http.rs
#	beacon_node/execution_layer/src/engine_api/json_structures.rs
#	beacon_node/execution_layer/src/test_utils/handle_rpc.rs
#	beacon_node/store/src/partial_beacon_state.rs
#	consensus/types/src/beacon_block.rs
#	consensus/types/src/beacon_block_body.rs
#	consensus/types/src/beacon_state.rs
#	consensus/types/src/config_and_preset.rs
#	consensus/types/src/execution_payload.rs
#	consensus/types/src/execution_payload_header.rs
#	consensus/types/src/light_client_optimistic_update.rs
#	consensus/types/src/payload.rs
#	lcli/src/parse_ssz.rs

consensus/state_processing/src/common/get_attesting_indices.rs

@@ -1,9 +1,9 @@
 use types::*;
 
 /// Returns validator indices which participated in the attestation, sorted by increasing index.
-pub fn get_attesting_indices<T: EthSpec>(
+pub fn get_attesting_indices<E: EthSpec>(
     committee: &[usize],
-    bitlist: &BitList<T::MaxValidatorsPerCommittee>,
+    bitlist: &BitList<E::MaxValidatorsPerCommittee>,
 ) -> Result<Vec<u64>, BeaconStateError> {
     if bitlist.len() != committee.len() {
         return Err(BeaconStateError::InvalidBitfield);
@@ -23,10 +23,10 @@ pub fn get_attesting_indices<T: EthSpec>(
 }
 
 /// Shortcut for getting the attesting indices while fetching the committee from the state's cache.
-pub fn get_attesting_indices_from_state<T: EthSpec>(
-    state: &BeaconState<T>,
-    att: &Attestation<T>,
+pub fn get_attesting_indices_from_state<E: EthSpec>(
+    state: &BeaconState<E>,
+    att: &Attestation<E>,
 ) -> Result<Vec<u64>, BeaconStateError> {
     let committee = state.get_beacon_committee(att.data.slot, att.data.index)?;
-    get_attesting_indices::<T>(committee.committee, &att.aggregation_bits)
+    get_attesting_indices::<E>(committee.committee, &att.aggregation_bits)
 }