Update US county-level maps with new Alaska census areas

[xaqrox]

Alaska's Valdez-Cordova Census Area was split into two new ones: the Chugach and Copper River Census Areas as of Jan 2, 2019 - here's the record from the US Census site: https://www.census.gov/programs-surveys/geography/technical-documentation/county-changes.2010.html#list-tab-957819518

The Census has the data needed as well: https://www.census.gov/geographies/mapping-files/time-series/geo/cartographic-boundary.html#:~:text=Select%20a%20State-,Congressional%20Districts%3A%20118th%20Congress,-1%20%3A%20500%2C000%20(national

[hubertkozik]

Hi @xaqrox! Thank you for reporting the new ticket. The ticket has been added to our internal discussion.

Internal note:
The Chugach has already been added into the Alaska map, it's possible to download it with an overpass query.

[out:json];
area["ISO3166-2"="US-AK"]->.ak;
(
rel(area.ak)["admin_level"="6"];
);
out body;
;
out skel qt;

Copper River Census Area is not added to the Alaska map, but it is present in OSM: https://www.openstreetmap.org/relation/2605315