internal/ethapi: don't return header size from rpc (ethereum#27347)

RPC methods `eth_getHeaderBy*` returned a size value which was meant for internal
processes. Please instead use `size` field returned by `eth_getBlockBy*` if you're interested
in the RLP encoded storage size of the block.

Signed-off-by: jsvisa <delweng@gmail.com>

internal/ethapi/api.go

@@ -1237,7 +1237,6 @@ func RPCMarshalHeader(head *types.Header) map[string]interface{} {
 		"miner":            head.Coinbase,
 		"difficulty":       (*hexutil.Big)(head.Difficulty),
 		"extraData":        hexutil.Bytes(head.Extra),
-		"size":             hexutil.Uint64(head.Size()),
 		"gasLimit":         hexutil.Uint64(head.GasLimit),
 		"gasUsed":          hexutil.Uint64(head.GasUsed),
 		"timestamp":        hexutil.Uint64(head.Time),