A *ListenerBindError that wraps syscall.EADDRINUSE now ends with a
"sudo ss -tlnp 'sport = :PORT'" pointer, and one wrapping
syscall.EACCES with a CAP_NET_BIND_SERVICE / setcap pointer. The
underlying chain is preserved via fmt.Errorf("%w"), so errors.Is /
errors.As continue to walk to the typed bind error and the syscall
errno.
Drop the "headscale ran into an error and had to shut down" wrap,
which only restated the symptom.
Export types.PortFromAddr so the classifier can render the port
number in the hint.
Updates #3227
Kristoffer Dalby
2114ced0d5