Update header encoding/decoding

A new field 'RequestsHash' was added to the header, and we needed to run
go generate to regenerate the generated encoding/decoding and also update
celo_block.go to account for the new field.

Simplified the encoding and decoding in celo_block.go by simply casting
the header into the right type for encoding/decoding. This ensures that
we won't need to update celo_block.go in the future when fields are
added or removed.

core/types/celo_block.go

@@ -61,27 +61,7 @@ func (h *Header) DecodeRLP(s *rlp.Stream) error {
 		// After gingerbread
 		decodedHeader := AfterGingerbreadHeader{}
 		err = rlp.DecodeBytes(raw, &decodedHeader)
-
-		h.ParentHash = decodedHeader.ParentHash
-		h.UncleHash = decodedHeader.UncleHash
-		h.Coinbase = decodedHeader.Coinbase
-		h.Root = decodedHeader.Root
-		h.TxHash = decodedHeader.TxHash
-		h.ReceiptHash = decodedHeader.ReceiptHash
-		h.Bloom = decodedHeader.Bloom
-		h.Difficulty = decodedHeader.Difficulty
-		h.Number = decodedHeader.Number
-		h.GasLimit = decodedHeader.GasLimit
-		h.GasUsed = decodedHeader.GasUsed
-		h.Time = decodedHeader.Time
-		h.Extra = decodedHeader.Extra
-		h.MixDigest = decodedHeader.MixDigest
-		h.Nonce = decodedHeader.Nonce
-		h.BaseFee = decodedHeader.BaseFee
-		h.WithdrawalsHash = decodedHeader.WithdrawalsHash
-		h.BlobGasUsed = decodedHeader.BlobGasUsed
-		h.ExcessBlobGas = decodedHeader.ExcessBlobGas
-		h.ParentBeaconRoot = decodedHeader.ParentBeaconRoot
+		*h = Header(decodedHeader)
 	}
 
 	return err
@@ -107,29 +87,7 @@ func (h *Header) EncodeRLP(w io.Writer) error {
 	}
 
 	// After gingerbread
-	encodedHeader := AfterGingerbreadHeader{
-		ParentHash:       h.ParentHash,
-		UncleHash:        h.UncleHash,
-		Coinbase:         h.Coinbase,
-		Root:             h.Root,
-		TxHash:           h.TxHash,
-		ReceiptHash:      h.ReceiptHash,
-		Bloom:            h.Bloom,
-		Difficulty:       h.Difficulty,
-		Number:           h.Number,
-		GasLimit:         h.GasLimit,
-		GasUsed:          h.GasUsed,
-		Time:             h.Time,
-		Extra:            h.Extra,
-		MixDigest:        h.MixDigest,
-		Nonce:            h.Nonce,
-		BaseFee:          h.BaseFee,
-		WithdrawalsHash:  h.WithdrawalsHash,
-		BlobGasUsed:      h.BlobGasUsed,
-		ExcessBlobGas:    h.ExcessBlobGas,
-		ParentBeaconRoot: h.ParentBeaconRoot,
-	}
-
+	encodedHeader := AfterGingerbreadHeader(*h)
 	return rlp.Encode(w, &encodedHeader)
 }