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

validator_client/src/http_metrics/metrics.rs

@@ -203,8 +203,8 @@ lazy_static::lazy_static! {
     );
 }
 
-pub fn gather_prometheus_metrics<T: EthSpec>(
-    ctx: &Context<T>,
+pub fn gather_prometheus_metrics<E: EthSpec>(
+    ctx: &Context<E>,
 ) -> std::result::Result<String, String> {
     let mut buffer = vec![];
     let encoder = TextEncoder::new();
@@ -221,7 +221,7 @@ pub fn gather_prometheus_metrics<T: EthSpec>(
 
         if let Some(duties_service) = &shared.duties_service {
             if let Some(slot) = duties_service.slot_clock.now() {
-                let current_epoch = slot.epoch(T::slots_per_epoch());
+                let current_epoch = slot.epoch(E::slots_per_epoch());
                 let next_epoch = current_epoch + 1;
 
                 set_int_gauge(

validator_client/src/http_metrics/mod.rs

@@ -34,18 +34,18 @@ impl From<String> for Error {
 }
 
 /// Contains objects which have shared access from inside/outside of the metrics server.
-pub struct Shared<T: EthSpec> {
-    pub validator_store: Option<Arc<ValidatorStore<SystemTimeSlotClock, T>>>,
-    pub duties_service: Option<Arc<DutiesService<SystemTimeSlotClock, T>>>,
+pub struct Shared<E: EthSpec> {
+    pub validator_store: Option<Arc<ValidatorStore<SystemTimeSlotClock, E>>>,
+    pub duties_service: Option<Arc<DutiesService<SystemTimeSlotClock, E>>>,
     pub genesis_time: Option<u64>,
 }
 
 /// A wrapper around all the items required to spawn the HTTP server.
 ///
 /// The server will gracefully handle the case where any fields are `None`.
-pub struct Context<T: EthSpec> {
+pub struct Context<E: EthSpec> {
     pub config: Config,
-    pub shared: RwLock<Shared<T>>,
+    pub shared: RwLock<Shared<E>>,
     pub log: Logger,
 }
 
@@ -86,8 +86,8 @@ impl Default for Config {
 ///
 /// Returns an error if the server is unable to bind or there is another error during
 /// configuration.
-pub fn serve<T: EthSpec>(
-    ctx: Arc<Context<T>>,
+pub fn serve<E: EthSpec>(
+    ctx: Arc<Context<E>>,
     shutdown: impl Future<Output = ()> + Send + Sync + 'static,
 ) -> Result<(SocketAddr, impl Future<Output = ()>), Error> {
     let config = &ctx.config;
@@ -118,7 +118,7 @@ pub fn serve<T: EthSpec>(
     let routes = warp::get()
         .and(warp::path("metrics"))
         .map(move || inner_ctx.clone())
-        .and_then(|ctx: Arc<Context<T>>| async move {
+        .and_then(|ctx: Arc<Context<E>>| async move {
             Ok::<_, warp::Rejection>(
                 metrics::gather_prometheus_metrics(&ctx)
                     .map(|body| {