server: add support to advertise onion addresses
server: add support to advertise onion addresses

In this commit, we allow `lnd` to properly parse onion addresses in
order to advertise them to the network when set through the
`--externalip` flag.

Co-Authored-By: Eugene <75ca2b81262d080125e72169f41e438fea01f0d9@users.noreply.github.com>

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