The find_my_address() function now prioritize the local interface over the
local hostname when guessing the IP address.
See proposal 312, section 3.2.1, general case:
https://gitweb.torproject.org/torspec.git/tree/proposals/312-relay-auto-ipv6-addr.txt#n359
The entire unit tests had to be refactored to make this possible. Instead of
hot patching it, it has been rewritten to cover all possible cases and the
test interface has been changed to accomodate both IPv4 and IPv6 in order for
them to be tested identically.
Closes#33238
Signed-off-by: David Goulet <dgoulet@torproject.org>