connmgr: update TorLookupIP to support parsing IPv6 addresses

[Roasbeef]

Today if the TorLookupIP is used to resolve a hostname, and the first IP returned is actually IPv6, then we'll end up erroring out here:

btcd/connmgr/tor.go

Line 120 in 780cc08

return nil, ErrTorInvalidAddressResponse

.

We should update this method to support IPv6 parsing by checking the length response, and parsing an IPv6 address accordingly. This python code may prove to be useful during implementation: https://github.com/torproject/tor/blob/main/contrib/client-tools/tor-resolve.py#L49.