[RefData][Tools] Simplified the Geonames extraction scripts.
 It has a few (minor) consequences, which changes however the
 format of the ORI/ori_por_public.csv generated data file:
 * When there is no ICAO code, that field is now empty.
 * The sorting order of the POR entries is now as following:
 ** IATA code (field #1)
 ** Geonames feature code (field #42)
 ** Geonames ID (field #5)
[RefData][ORI] Removed the ZZZZ string from the ICAO field (they are now actually empty).
[RefData][ORI] Fixed HEX/Herrera (DO), JBQ/Higuero (DO) and SBD/San Bernardino (CA, USA).