Connect to the addresses from `getaddrinfo(3)`,
alternating between address family,
starting with ipv6 and wait `fetchConnDelay`
between each connection attempt.
If a connection is established within the attempts,
use this connection and close all others.
If `connect(3)` returns `ENETUNREACH`, don't attempt more
connections with the failing address family.
If there are no more addresses to attempt,
wait for `fetchConnTimeout` and return the first established
connection.
If no connection was established within the timeouts,
close all sockets and return -1 and set errno to
`ETIMEDOUT`.
