[RPC] Add transaction size to JSON output
[RPC] Add transaction size to JSON output

This may be useful for blockchain explorers.

bitcoinxt/bitcoinxt,dagurval/bitcoinxt,dagurval/bitcoinxt,bitcoinxt/bitcoinxt,dagurval/bitcoinxt,dagurval/bitcoinxt,bitcoinxt/bitcoinxt,bitcoinxt/bitcoinxt,bitcoinxt/bitcoinxt,bitcoinxt/bitcoinxt,dagurval/bitcoinxt,dagurval/bitcoinxt