RPC RequestId Cleanup (#7238)

I've been working at updating another library to latest Lighthouse and got very confused with RPC request Ids.

There were types that had fields called `request_id` and `id`. And interchangeably could have types `PeerRequestId`, `rpc::RequestId`, `AppRequestId`, `api_types::RequestId` or even `Request.id`.

I couldn't keep track of which Id was linked to what and what each type meant.

So this PR mainly does a few things:
- Changes the field naming to match the actual type. So any field that has an  `AppRequestId` will be named `app_request_id` rather than `id` or `request_id` for example.
- I simplified the types. I removed the two different `RequestId` types (one in Lighthouse_network the other in the rpc) and grouped them into one. It has one downside tho. I had to add a few unreachable lines of code in the beacon processor, which the extra type would prevent, but I feel like it might be worth it. Happy to add an extra type to avoid those few lines.
- I also removed the concept of `PeerRequestId` which sometimes went alongside a `request_id`. There were times were had a `PeerRequest` and a `Request` being returned, both of which contain a `RequestId` so we had redundant information. I've simplified the logic by removing `PeerRequestId` and made a `ResponseId`. I think if you look at the code changes, it simplifies things a bit and removes the redundant extra info.

I think with this PR things are a little bit easier to reasonable about what is going on with all these RPC Ids.

NOTE: I did this with the help of AI, so probably should be checked

beacon_node/network/src/sync/manager.rs

@@ -108,7 +108,7 @@ pub enum SyncMessage<E: EthSpec> {
 
     /// A block has been received from the RPC.
     RpcBlock {
-        request_id: SyncRequestId,
+        sync_request_id: SyncRequestId,
         peer_id: PeerId,
         beacon_block: Option<Arc<SignedBeaconBlock<E>>>,
         seen_timestamp: Duration,
@@ -116,7 +116,7 @@ pub enum SyncMessage<E: EthSpec> {
 
     /// A blob has been received from the RPC.
     RpcBlob {
-        request_id: SyncRequestId,
+        sync_request_id: SyncRequestId,
         peer_id: PeerId,
         blob_sidecar: Option<Arc<BlobSidecar<E>>>,
         seen_timestamp: Duration,
@@ -124,7 +124,7 @@ pub enum SyncMessage<E: EthSpec> {
 
     /// A data columns has been received from the RPC
     RpcDataColumn {
-        request_id: SyncRequestId,
+        sync_request_id: SyncRequestId,
         peer_id: PeerId,
         data_column: Option<Arc<DataColumnSidecar<E>>>,
         seen_timestamp: Duration,
@@ -153,7 +153,7 @@ pub enum SyncMessage<E: EthSpec> {
     /// An RPC Error has occurred on a request.
     RpcError {
         peer_id: PeerId,
-        request_id: SyncRequestId,
+        sync_request_id: SyncRequestId,
         error: RPCError,
     },
 
@@ -477,9 +477,9 @@ impl<T: BeaconChainTypes> SyncManager<T> {
     }
 
     /// Handles RPC errors related to requests that were emitted from the sync manager.
-    fn inject_error(&mut self, peer_id: PeerId, request_id: SyncRequestId, error: RPCError) {
+    fn inject_error(&mut self, peer_id: PeerId, sync_request_id: SyncRequestId, error: RPCError) {
         trace!("Sync manager received a failed RPC");
-        match request_id {
+        match sync_request_id {
             SyncRequestId::SingleBlock { id } => {
                 self.on_single_block_response(id, peer_id, RpcEvent::RPCError(error))
             }
@@ -509,8 +509,8 @@ impl<T: BeaconChainTypes> SyncManager<T> {
     fn peer_disconnect(&mut self, peer_id: &PeerId) {
         // Inject a Disconnected error on all requests associated with the disconnected peer
         // to retry all batches/lookups
-        for request_id in self.network.peer_disconnected(peer_id) {
-            self.inject_error(*peer_id, request_id, RPCError::Disconnected);
+        for sync_request_id in self.network.peer_disconnected(peer_id) {
+            self.inject_error(*peer_id, sync_request_id, RPCError::Disconnected);
         }
 
         // Remove peer from all data structures
@@ -751,25 +751,27 @@ impl<T: BeaconChainTypes> SyncManager<T> {
                 self.add_peers_force_range_sync(&peers, head_root, head_slot);
             }
             SyncMessage::RpcBlock {
-                request_id,
+                sync_request_id,
                 peer_id,
                 beacon_block,
                 seen_timestamp,
             } => {
-                self.rpc_block_received(request_id, peer_id, beacon_block, seen_timestamp);
+                self.rpc_block_received(sync_request_id, peer_id, beacon_block, seen_timestamp);
             }
             SyncMessage::RpcBlob {
-                request_id,
+                sync_request_id,
                 peer_id,
                 blob_sidecar,
                 seen_timestamp,
-            } => self.rpc_blob_received(request_id, peer_id, blob_sidecar, seen_timestamp),
+            } => self.rpc_blob_received(sync_request_id, peer_id, blob_sidecar, seen_timestamp),
             SyncMessage::RpcDataColumn {
-                request_id,
+                sync_request_id,
                 peer_id,
                 data_column,
                 seen_timestamp,
-            } => self.rpc_data_column_received(request_id, peer_id, data_column, seen_timestamp),
+            } => {
+                self.rpc_data_column_received(sync_request_id, peer_id, data_column, seen_timestamp)
+            }
             SyncMessage::UnknownParentBlock(peer_id, block, block_root) => {
                 let block_slot = block.slot();
                 let parent_root = block.parent_root();
@@ -845,9 +847,9 @@ impl<T: BeaconChainTypes> SyncManager<T> {
             }
             SyncMessage::RpcError {
                 peer_id,
-                request_id,
+                sync_request_id,
                 error,
-            } => self.inject_error(peer_id, request_id, error),
+            } => self.inject_error(peer_id, sync_request_id, error),
             SyncMessage::BlockComponentProcessed {
                 process_type,
                 result,
@@ -1018,12 +1020,12 @@ impl<T: BeaconChainTypes> SyncManager<T> {
 
     fn rpc_block_received(
         &mut self,
-        request_id: SyncRequestId,
+        sync_request_id: SyncRequestId,
         peer_id: PeerId,
         block: Option<Arc<SignedBeaconBlock<T::EthSpec>>>,
         seen_timestamp: Duration,
     ) {
-        match request_id {
+        match sync_request_id {
             SyncRequestId::SingleBlock { id } => self.on_single_block_response(
                 id,
                 peer_id,
@@ -1060,12 +1062,12 @@ impl<T: BeaconChainTypes> SyncManager<T> {
 
     fn rpc_blob_received(
         &mut self,
-        request_id: SyncRequestId,
+        sync_request_id: SyncRequestId,
         peer_id: PeerId,
         blob: Option<Arc<BlobSidecar<T::EthSpec>>>,
         seen_timestamp: Duration,
     ) {
-        match request_id {
+        match sync_request_id {
             SyncRequestId::SingleBlob { id } => self.on_single_blob_response(
                 id,
                 peer_id,
@@ -1084,12 +1086,12 @@ impl<T: BeaconChainTypes> SyncManager<T> {
 
     fn rpc_data_column_received(
         &mut self,
-        request_id: SyncRequestId,
+        sync_request_id: SyncRequestId,
         peer_id: PeerId,
         data_column: Option<Arc<DataColumnSidecar<T::EthSpec>>>,
         seen_timestamp: Duration,
     ) {
-        match request_id {
+        match sync_request_id {
             SyncRequestId::DataColumnsByRoot(req_id) => {
                 self.on_data_columns_by_root_response(
                     req_id,