htlcswitch: failAddPacket with full packet information
htlcswitch: failAddPacket with full packet information

This commit sets more fields on the htlcPacket created to fail adding
a htlc packet to the switch for notification purposes. This new data is
copied by value from the original packet. The packet is then failed
back to the peer that forwarded us the packet, which is handled by
handledownstream packet. The values added to the packet are not used
in the handling of a failed packet.

aakselrod/lnd,aakselrod/lnd,LightningNetwork/lnd,LightningNetwork/lnd