Fix clippy warnings (#1385)

## Issue Addressed

NA

## Proposed Changes

Fixes most clippy warnings and ignores the rest of them, see issue #1388.

consensus/proto_array/src/proto_array_fork_choice.rs

@@ -95,7 +95,7 @@ impl ProtoArrayForkChoice {
             .map_err(|e| format!("Failed to add finalized block to proto_array: {:?}", e))?;
 
         Ok(Self {
-            proto_array: proto_array,
+            proto_array,
             votes: ElasticList::default(),
             balances: vec![],
         })
@@ -171,6 +171,10 @@ impl ProtoArrayForkChoice {
         self.proto_array.nodes.len()
     }
 
+    pub fn is_empty(&self) -> bool {
+        self.proto_array.nodes.is_empty()
+    }
+
     pub fn contains_block(&self, block_root: &Hash256) -> bool {
         self.proto_array.indices.contains_key(block_root)
     }