feat: add method to EthBuiltPayload to get blob sidecars (#7979)

Co-authored-by: Matthias Seitz <matthias.seitz@outlook.de>

crates/ethereum/engine-primitives/src/payload.rs

@@ -57,6 +57,11 @@ impl EthBuiltPayload {
         self.fees
     }
 
+    /// Returns the blob sidecars.
+    pub fn sidecars(&self) -> &[BlobTransactionSidecar] {
+        &self.sidecars
+    }
+
     /// Adds sidecars to the payload.
     pub fn extend_sidecars(&mut self, sidecars: Vec<BlobTransactionSidecar>) {
         self.sidecars.extend(sidecars)