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

testing/ef_tests/src/case_result.rs

@@ -32,9 +32,9 @@ impl CaseResult {
 
 /// Same as `compare_result_detailed`, however it drops the caches on both states before
 /// comparison.
-pub fn compare_beacon_state_results_without_caches<T: EthSpec, E: Debug>(
-    result: &mut Result<BeaconState<T>, E>,
-    expected: &mut Option<BeaconState<T>>,
+pub fn compare_beacon_state_results_without_caches<E: EthSpec, T: Debug>(
+    result: &mut Result<BeaconState<E>, T>,
+    expected: &mut Option<BeaconState<E>>,
 ) -> Result<(), Error> {
     if let (Ok(ref mut result), Some(ref mut expected)) = (result.as_mut(), expected.as_mut()) {
         result.drop_all_caches().unwrap();
@@ -46,13 +46,13 @@ pub fn compare_beacon_state_results_without_caches<T: EthSpec, E: Debug>(
 
 /// Same as `compare_result`, however utilizes the `CompareFields` trait to give a list of
 /// mismatching fields when `Ok(result) != Some(expected)`.
-pub fn compare_result_detailed<T, E>(
-    result: &Result<T, E>,
+pub fn compare_result_detailed<T, U>(
+    result: &Result<T, U>,
     expected: &Option<T>,
 ) -> Result<(), Error>
 where
     T: PartialEq<T> + Debug + CompareFields,
-    E: Debug,
+    U: Debug,
 {
     match (result, expected) {
         (Ok(result), Some(expected)) => {
@@ -84,10 +84,10 @@ where
 ///
 /// If `expected.is_none()` then `result` is expected to be `Err`. Otherwise, `T` in `result` and
 /// `expected` must be equal.
-pub fn compare_result<T, E>(result: &Result<T, E>, expected: &Option<T>) -> Result<(), Error>
+pub fn compare_result<T, U>(result: &Result<T, U>, expected: &Option<T>) -> Result<(), Error>
 where
     T: PartialEq<T> + Debug,
-    E: Debug,
+    U: Debug,
 {
     match (result, expected) {
         // Pass: The should have failed and did fail.