Clippy clean (#536)

* Change into_iter to iter

* Fix clippy 'easy' warnings

* Clippy eth2/utils

* Add struct NetworkInfo

* Clippy for types, utils, and beacon_node/store/src/iters.rs

* Cargo fmt

* Change foo to my_foo

* Remove complex signature

* suppress clippy warning for unit_value in benches

* Use enumerate instead of iterating over range

* Allow trivially_copy_pass_by_ref in serde_utils

eth2/lmd_ghost/src/reduced_tree.rs

@@ -246,7 +246,7 @@ where
 
     pub fn latest_message(&self, validator_index: usize) -> Option<(Hash256, Slot)> {
         match self.latest_votes.get_ref(validator_index) {
-            Some(Some(v)) => Some((v.hash.clone(), v.slot.clone())),
+            Some(Some(v)) => Some((v.hash, v.slot)),
             _ => None,
         }
     }