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

beacon_node/operation_pool/src/attestation.rs

@@ -12,17 +12,17 @@ use types::{
 };
 
 #[derive(Debug, Clone)]
-pub struct AttMaxCover<'a, T: EthSpec> {
+pub struct AttMaxCover<'a, E: EthSpec> {
     /// Underlying attestation.
-    pub att: AttestationRef<'a, T>,
+    pub att: AttestationRef<'a, E>,
     /// Mapping of validator indices and their rewards.
     pub fresh_validators_rewards: HashMap<u64, u64>,
 }
 
-impl<'a, T: EthSpec> AttMaxCover<'a, T> {
+impl<'a, E: EthSpec> AttMaxCover<'a, E> {
     pub fn new(
-        att: AttestationRef<'a, T>,
-        state: &BeaconState<T>,
+        att: AttestationRef<'a, E>,
+        state: &BeaconState<E>,
         reward_cache: &'a RewardCache,
         total_active_balance: u64,
         spec: &ChainSpec,
@@ -36,9 +36,9 @@ impl<'a, T: EthSpec> AttMaxCover<'a, T> {
 
     /// Initialise an attestation cover object for base/phase0 hard fork.
     pub fn new_for_base(
-        att: AttestationRef<'a, T>,
-        state: &BeaconState<T>,
-        base_state: &BeaconStateBase<T>,
+        att: AttestationRef<'a, E>,
+        state: &BeaconState<E>,
+        base_state: &BeaconStateBase<E>,
         total_active_balance: u64,
         spec: &ChainSpec,
     ) -> Option<Self> {
@@ -46,7 +46,7 @@ impl<'a, T: EthSpec> AttMaxCover<'a, T> {
         let committee = state
             .get_beacon_committee(att.data.slot, att.data.index)
             .ok()?;
-        let indices = get_attesting_indices::<T>(committee.committee, &fresh_validators).ok()?;
+        let indices = get_attesting_indices::<E>(committee.committee, &fresh_validators).ok()?;
         let fresh_validators_rewards: HashMap<u64, u64> = indices
             .iter()
             .copied()
@@ -70,8 +70,8 @@ impl<'a, T: EthSpec> AttMaxCover<'a, T> {
 
     /// Initialise an attestation cover object for Altair or later.
     pub fn new_for_altair_deneb(
-        att: AttestationRef<'a, T>,
-        state: &BeaconState<T>,
+        att: AttestationRef<'a, E>,
+        state: &BeaconState<E>,
         reward_cache: &'a RewardCache,
         total_active_balance: u64,
         spec: &ChainSpec,
@@ -123,16 +123,16 @@ impl<'a, T: EthSpec> AttMaxCover<'a, T> {
     }
 }
 
-impl<'a, T: EthSpec> MaxCover for AttMaxCover<'a, T> {
-    type Object = Attestation<T>;
-    type Intermediate = AttestationRef<'a, T>;
+impl<'a, E: EthSpec> MaxCover for AttMaxCover<'a, E> {
+    type Object = Attestation<E>;
+    type Intermediate = AttestationRef<'a, E>;
     type Set = HashMap<u64, u64>;
 
-    fn intermediate(&self) -> &AttestationRef<'a, T> {
+    fn intermediate(&self) -> &AttestationRef<'a, E> {
         &self.att
     }
 
-    fn convert_to_object(att_ref: &AttestationRef<'a, T>) -> Attestation<T> {
+    fn convert_to_object(att_ref: &AttestationRef<'a, E>) -> Attestation<E> {
         att_ref.clone_as_attestation()
     }
 
@@ -152,7 +152,7 @@ impl<'a, T: EthSpec> MaxCover for AttMaxCover<'a, T> {
     /// of slashable voting, which is rare.
     fn update_covering_set(
         &mut self,
-        best_att: &AttestationRef<'a, T>,
+        best_att: &AttestationRef<'a, E>,
         covered_validators: &HashMap<u64, u64>,
     ) {
         if self.att.data.slot == best_att.data.slot && self.att.data.index == best_att.data.index {
@@ -175,11 +175,11 @@ impl<'a, T: EthSpec> MaxCover for AttMaxCover<'a, T> {
 /// removed from the `aggregation_bits` before returning it.
 ///
 /// This isn't optimal, but with the Altair fork this code is obsolete and not worth upgrading.
-pub fn earliest_attestation_validators<T: EthSpec>(
-    attestation: &AttestationRef<T>,
-    state: &BeaconState<T>,
-    base_state: &BeaconStateBase<T>,
-) -> BitList<T::MaxValidatorsPerCommittee> {
+pub fn earliest_attestation_validators<E: EthSpec>(
+    attestation: &AttestationRef<E>,
+    state: &BeaconState<E>,
+    base_state: &BeaconStateBase<E>,
+) -> BitList<E::MaxValidatorsPerCommittee> {
     // Bitfield of validators whose attestations are new/fresh.
     let mut new_validators = attestation.indexed.aggregation_bits.clone();