Add counterparty channel ID to OnChanOpenAck callback

[colin-axner]

The spec provides the portID, channelID, and version as the arguments to OnChanOpenAck, but the counterparty channel ID might be set for the first time in this callback (it is empty on ChanOpenInit). The counterparty channel ID should be added to the application callbacks since the channel state is written after the callback is performed. Applications may need access to this information

Ref code in spec:

function handleChanOpenAck(datagram: ChanOpenAck) {
    err = module.onChanOpenAck(
      datagram.portIdentifier,
      datagram.channelIdentifier,
      datagram.version
    )
    abortTransactionUnless(err === nil)
    handler.chanOpenAck(
      datagram.portIdentifier,
      datagram.channelIdentifier,
      datagram.version,
      datagram.proofTry,
      datagram.proofHeight
    )
}

Ref issue on ibc-go #1075

[colin-axner]

closed by #676