Add a filter code for a range of ICAO 24-bit addresses

This code is to reduce the non-informational regular traffic such as the periodic signals for the local transponders by filtering them with ICAO 24-bit addresses.  The filtered contents will not show up to the external feeds on TCP port 30001, 30002, and 30003, though they are visible on the port 8080 HTTP server. I find this filtering useful to reduce processing load for feeding from dump1090 to Flightradar24.

I've made it as an `#ifdef` clause so that this code will not change the default behavior.