Add sync lookup custody request state (#6257)

* Add sync lookup custody request state

* Review PR

* clippy

* Merge branch 'unstable' of https://github.com/sigp/lighthouse into peerdas-network-lookup

beacon_node/beacon_chain/src/beacon_chain.rs

@@ -6852,6 +6852,24 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
         self.data_availability_checker.data_availability_boundary()
     }
 
+    /// Returns true if epoch is within the data availability boundary
+    pub fn da_check_required_for_epoch(&self, epoch: Epoch) -> bool {
+        self.data_availability_checker
+            .da_check_required_for_epoch(epoch)
+    }
+
+    /// Returns true if we should fetch blobs for this block
+    pub fn should_fetch_blobs(&self, block_epoch: Epoch) -> bool {
+        self.da_check_required_for_epoch(block_epoch)
+            && !self.spec.is_peer_das_enabled_for_epoch(block_epoch)
+    }
+
+    /// Returns true if we should fetch custody columns for this block
+    pub fn should_fetch_custody_columns(&self, block_epoch: Epoch) -> bool {
+        self.da_check_required_for_epoch(block_epoch)
+            && self.spec.is_peer_das_enabled_for_epoch(block_epoch)
+    }
+
     pub fn logger(&self) -> &Logger {
         &self.log
     }