Rework internal rpc protocol handling (#4290)

## Issue Addressed

Resolves #3980. Builds on work by @GeemoCandama in #4084 

## Proposed Changes

Extends the `SupportedProtocol` abstraction added in Geemo's PR and attempts to fix internal versioning of requests that are mentioned in this comment https://github.com/sigp/lighthouse/pull/4084#issuecomment-1496380033 

Co-authored-by: geemo <geemo@tutanota.com>

beacon_node/network/src/sync/block_lookups/single_block_lookup.rs

@@ -156,9 +156,7 @@ impl<const MAX_ATTEMPTS: u8> SingleBlockRequest<MAX_ATTEMPTS> {
                 cannot_process: self.failed_processing >= self.failed_downloading,
             })
         } else if let Some(&peer_id) = self.available_peers.iter().choose(&mut rand::thread_rng()) {
-            let request = BlocksByRootRequest {
-                block_roots: VariableList::from(vec![self.hash]),
-            };
+            let request = BlocksByRootRequest::new(VariableList::from(vec![self.hash]));
             self.state = State::Downloading { peer_id };
             self.used_peers.insert(peer_id);
             Ok((peer_id, request))

beacon_node/network/src/sync/network_context.rs

@@ -112,7 +112,7 @@ impl<T: BeaconChainTypes> SyncNetworkContext<T> {
             self.log,
             "Sending BlocksByRange Request";
             "method" => "BlocksByRange",
-            "count" => request.count,
+            "count" => request.count(),
             "peer" => %peer_id,
         );
         let request = Request::BlocksByRange(request);
@@ -138,7 +138,7 @@ impl<T: BeaconChainTypes> SyncNetworkContext<T> {
             self.log,
             "Sending backfill BlocksByRange Request";
             "method" => "BlocksByRange",
-            "count" => request.count,
+            "count" => request.count(),
             "peer" => %peer_id,
         );
         let request = Request::BlocksByRange(request);
@@ -185,7 +185,7 @@ impl<T: BeaconChainTypes> SyncNetworkContext<T> {
             self.log,
             "Sending BlocksByRoot Request";
             "method" => "BlocksByRoot",
-            "count" => request.block_roots.len(),
+            "count" => request.block_roots().len(),
             "peer" => %peer_id
         );
         let request = Request::BlocksByRoot(request);
@@ -209,7 +209,7 @@ impl<T: BeaconChainTypes> SyncNetworkContext<T> {
             self.log,
             "Sending BlocksByRoot Request";
             "method" => "BlocksByRoot",
-            "count" => request.block_roots.len(),
+            "count" => request.block_roots().len(),
             "peer" => %peer_id
         );
         let request = Request::BlocksByRoot(request);

beacon_node/network/src/sync/range_sync/batch.rs

@@ -202,10 +202,10 @@ impl<T: EthSpec, B: BatchConfig> BatchInfo<T, B> {
 
     /// Returns a BlocksByRange request associated with the batch.
     pub fn to_blocks_by_range_request(&self) -> BlocksByRangeRequest {
-        BlocksByRangeRequest {
-            start_slot: self.start_slot.into(),
-            count: self.end_slot.sub(self.start_slot).into(),
-        }
+        BlocksByRangeRequest::new(
+            self.start_slot.into(),
+            self.end_slot.sub(self.start_slot).into(),
+        )
     }
 
     /// After different operations over a batch, this could be in a state that allows it to