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/base.rs

@@ -3,8 +3,8 @@ use safe_arith::SafeArith;
 use types::*;
 
 /// Returns the base reward for some validator.
-pub fn get_base_reward<T: EthSpec>(
-    state: &BeaconState<T>,
+pub fn get_base_reward<E: EthSpec>(
+    state: &BeaconState<E>,
     index: usize,
     // Should be == get_total_active_balance(state, spec)
     total_active_balance: u64,
@@ -18,7 +18,7 @@ pub fn get_base_reward<T: EthSpec>(
         .map_err(Into::into)
 }
 
-pub fn get_base_reward_from_effective_balance<T: EthSpec>(
+pub fn get_base_reward_from_effective_balance<E: EthSpec>(
     effective_balance: u64,
     total_active_balance: u64,
     spec: &ChainSpec,