Refresh active station list and correlation data

Perform a fresh build of data sets from current sources, and add a
few additional overrides for previously unknown stations. Also
update from 2019 to 2021 US Census data, from March 2020 to
September 2021 CountyZone maps, and from 2020-08-29 to 2021-08-29
airport IDs and active METAR stations/WX zones.