Request manager: Handle blobless blocks (#4833)

Post-Deneb, when the request manager receives a missing block from a
peer, it needs to check if the corresponding blobs are available, and
if so pass them along. If they aren't available, the newly-fetched
block must be put in blobless quarantine (while the blobs are
retrieved, coming in next commit).

beacon_chain/nimbus_beacon_node.nim

@@ -340,6 +340,30 @@ proc initFullNode(
                                 resfut,
                                 maybeFinalized = maybeFinalized)
       resfut
+    rmanBlockVerifier =  proc(signedBlock: ForkedSignedBeaconBlock,
+                              maybeFinalized: bool):
+        Future[Result[void, VerifierError]] =
+      let resfut = newFuture[Result[void, VerifierError]]("rmanBlockVerifier")
+      withBlck(signedBlock):
+        when typeof(blck).toFork() >= ConsensusFork.Deneb:
+          if not blobQuarantine[].hasBlobs(blck):
+            # We don't have all the blobs for this block, so we have
+            # to put it in blobless quarantine.
+            if not quarantine[].addBlobless(dag.finalizedHead.slot, blck):
+              let e = Result[void, VerifierError].err(VerifierError.UnviableFork)
+              resfut.complete(e)
+            return
+          let blobs = blobQuarantine[].popBlobs(blck.root)
+          blockProcessor[].addBlock(MsgSource.gossip, signedBlock,
+                                    blobs,
+                                    resfut,
+                                    maybeFinalized = maybeFinalized)
+        else:
+          blockProcessor[].addBlock(MsgSource.gossip, signedBlock,
+                                    BlobSidecars @[],
+                                    resfut,
+                                    maybeFinalized = maybeFinalized)
+      resfut
     processor = Eth2Processor.new(
       config.doppelgangerDetection,
       blockProcessor, node.validatorMonitor, dag, attestationPool,
@@ -390,7 +414,7 @@ proc initFullNode(
   node.requestManager = RequestManager.init(node.network,
                                             dag.cfg.DENEB_FORK_EPOCH,
                                             getBeaconTime,
-                                            blockVerifier)
+                                            rmanBlockVerifier)
   node.syncManager = syncManager
   node.backfiller = backfiller
   node.router = router

beacon_chain/sync/request_manager.nim

@@ -32,8 +32,7 @@ const
 
 type
   BlockVerifier* =
-    proc(signedBlock: ForkedSignedBeaconBlock, blobs: BlobSidecars,
+    proc(signedBlock: ForkedSignedBeaconBlock, maybeFinalized: bool):
-         maybeFinalized: bool):
       Future[Result[void, VerifierError]] {.gcsafe, raises: [Defect].}
   RequestManager* = object
     network*: Eth2Node
@@ -91,9 +90,7 @@ proc fetchAncestorBlocksFromNetwork(rman: RequestManager,
           gotUnviableBlock = false
 
         for b in ublocks:
-          let ver = await rman.blockVerifier(b[], BlobSidecars @[], false)
+          let ver = await rman.blockVerifier(b[], false)
-          # TODO:
-          # blob handling for Deneb blocks
           if ver.isErr():
             case ver.error()
             of VerifierError.MissingParent: