ICS 04(upgrades): missing setting counterparty's last packet sent

[crodriguezvega]

In chanUpgradeAck and chanUpgradeConfirm we miss setting the counterparty's last packet sent in the private store. Something like this:

// store counterparty's sequence number of last packet sent
privateStore.set(
  channelCounterpartyLastPacketSequencePath(portIdentifier, channelIdentifier), 
  counterpartyUpgrade.lastPacketSent
)

This is needed so that in recvPacket it is possible to check that we receive packets that have been sent before the last packet sent by the counterparty:

counterpartyLastPacketSent = privateStore.get(channelCounterpartyLastPacketSequencePath(packet.destPort, packet.destChannel)
abortTransactionUnless(channel.state === OPEN || (channel.state === FLUSHING && packet.sequence <= counterpartyLastPacketSent))