Ensure payload envelope streamer always serves canonical envelopes after the split slot (#9085)

Co-Authored-By: Eitan Seri- Levi <eserilev@gmail.com>

Co-Authored-By: Eitan Seri-Levi <eserilev@ucsc.edu>

consensus/fork_choice/src/fork_choice.rs

@@ -78,6 +78,7 @@ pub enum Error<T> {
     UnrealizedVoteProcessing(state_processing::EpochProcessingError),
     ValidatorStatuses(BeaconStateError),
     ChainSpecError(String),
+    DoesNotDescendFromFinalizedCheckpoint,
 }
 
 impl<T> From<InvalidAttestation> for Error<T> {
@@ -1523,6 +1524,29 @@ where
         }
     }
 
+    /// Returns the canonical payload status of a block. See
+    /// `ProtoArrayForkChoice::get_canonical_payload_status`.
+    pub fn get_canonical_payload_status(
+        &self,
+        block_root: &Hash256,
+        spec: &ChainSpec,
+    ) -> Result<PayloadStatus, Error<T::Error>> {
+        if self.is_finalized_checkpoint_or_descendant(*block_root) {
+            let current_slot = self.fc_store.get_current_slot();
+            let proposer_boost_root = self.fc_store.proposer_boost_root();
+            self.proto_array
+                .get_canonical_payload_status::<E>(
+                    block_root,
+                    current_slot,
+                    proposer_boost_root,
+                    spec,
+                )
+                .map_err(Error::ProtoArrayError)
+        } else {
+            Err(Error::DoesNotDescendFromFinalizedCheckpoint)
+        }
+    }
+
     /// Returns the weight for the given block root.
     pub fn get_block_weight(&self, block_root: &Hash256) -> Option<u64> {
         self.proto_array.get_weight(block_root)