internal/ethapi: add support for blobs in eth_fillTransaction (#28839)

This change adds support for blob-transaction in certain API-endpoints, e.g. eth_fillTransaction. A follow-up PR will add support for signing such transactions.

core/types/transaction_marshalling.go

@@ -23,6 +23,7 @@ import (
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/ethereum/go-ethereum/crypto/kzg4844"
 	"github.com/holiman/uint256"
 )
 
@@ -47,6 +48,11 @@ type txJSON struct {
 	S                    *hexutil.Big    `json:"s"`
 	YParity              *hexutil.Uint64 `json:"yParity,omitempty"`
 
+	// Blob transaction sidecar encoding:
+	Blobs       []kzg4844.Blob       `json:"blobs,omitempty"`
+	Commitments []kzg4844.Commitment `json:"commitments,omitempty"`
+	Proofs      []kzg4844.Proof      `json:"proofs,omitempty"`
+
 	// Only used for encoding:
 	Hash common.Hash `json:"hash"`
 }
@@ -142,6 +148,11 @@ func (tx *Transaction) MarshalJSON() ([]byte, error) {
 		enc.S = (*hexutil.Big)(itx.S.ToBig())
 		yparity := itx.V.Uint64()
 		enc.YParity = (*hexutil.Uint64)(&yparity)
+		if sidecar := itx.Sidecar; sidecar != nil {
+			enc.Blobs = itx.Sidecar.Blobs
+			enc.Commitments = itx.Sidecar.Commitments
+			enc.Proofs = itx.Sidecar.Proofs
+		}
 	}
 	return json.Marshal(&enc)
 }