ids-functions.pl: Add generate_service_ports_file() function.

ids-functions.pl: Add generate_service_ports_file() function.

This function calls the subfunctions from the port helpers library file
to gather all the available services and to collect their used ports.

That details will be written to a yaml file which can be used by suricata
in various rules files.

Signed-off-by: Stefan Schantl <stefan.schantl@ipfire.org>