Offloading KZG Proof Computation from the beacon node (#7117)

Addresses #7108

- Add EL integration for `getPayloadV5` and `getBlobsV2`
- Offload proof computation and use proofs from EL RPC APIs

beacon_node/beacon_chain/src/data_column_verification.rs

@@ -141,13 +141,23 @@ pub enum GossipDataColumnError {
     ///
     /// The column sidecar is invalid and the peer is faulty
     UnexpectedDataColumn,
-    /// The data column length must be equal to the number of commitments/proofs, otherwise the
+    /// The data column length must be equal to the number of commitments, otherwise the
     /// sidecar is invalid.
     ///
     /// ## Peer scoring
     ///
     /// The column sidecar is invalid and the peer is faulty
-    InconsistentCommitmentsOrProofLength,
+    InconsistentCommitmentsLength {
+        cells_len: usize,
+        commitments_len: usize,
+    },
+    /// The data column length must be equal to the number of proofs, otherwise the
+    /// sidecar is invalid.
+    ///
+    /// ## Peer scoring
+    ///
+    /// The column sidecar is invalid and the peer is faulty
+    InconsistentProofsLength { cells_len: usize, proofs_len: usize },
 }
 
 impl From<BeaconChainError> for GossipDataColumnError {
@@ -240,6 +250,14 @@ impl<E: EthSpec> KzgVerifiedDataColumn<E> {
         verify_kzg_for_data_column(data_column, kzg)
     }
 
+    /// Create a `KzgVerifiedDataColumn` from `data_column` that are already KZG verified.
+    ///
+    /// This should be used with caution, as used incorrectly it could result in KZG verification
+    /// being skipped and invalid data_columns being deemed valid.
+    pub fn from_verified(data_column: Arc<DataColumnSidecar<E>>) -> Self {
+        Self { data: data_column }
+    }
+
     pub fn from_batch(
         data_columns: Vec<Arc<DataColumnSidecar<E>>>,
         kzg: &Kzg,
@@ -473,10 +491,23 @@ fn verify_data_column_sidecar<E: EthSpec>(
     if data_column.kzg_commitments.is_empty() {
         return Err(GossipDataColumnError::UnexpectedDataColumn);
     }
-    if data_column.column.len() != data_column.kzg_commitments.len()
-        || data_column.column.len() != data_column.kzg_proofs.len()
-    {
-        return Err(GossipDataColumnError::InconsistentCommitmentsOrProofLength);
+
+    let cells_len = data_column.column.len();
+    let commitments_len = data_column.kzg_commitments.len();
+    let proofs_len = data_column.kzg_proofs.len();
+
+    if cells_len != commitments_len {
+        return Err(GossipDataColumnError::InconsistentCommitmentsLength {
+            cells_len,
+            commitments_len,
+        });
+    }
+
+    if cells_len != proofs_len {
+        return Err(GossipDataColumnError::InconsistentProofsLength {
+            cells_len,
+            proofs_len,
+        });
     }
 
     Ok(())