Fix mDNS support for network printers.

At least on FreeBSD 13, SO_REUSEPORT is no longer sufficient when Avahi
already uses port 5353. It seems that port reuse is only allowed for
processes from the same user now. But even if Avahi is not running and
port 5353 is available my printer still failed to be detected. According
to RFC 6762 only fully compliant queriers should be using that port which
HPLIP isn't. I suspect the printer is sending responses that HPLIP can't
parse. Patch HPLIP to use a simple socket (dynamically allocated port)
which is enough for the one-shot mDNS queries it performs.

Now my printer is detected by "hp-probe --method=mdns" and xsane can find
the scanner part using the hpaio plugin.

PR: 247723
Approved by: maintainer timeout (19 days)