Fix other civs being able to upgrade Han CC to Court.
This ensures the {civ} and {native} tags are (properly) supported for upgrades and uses it for the Han CC.
Reported on the forums (https://wildfiregames.com/forum/topic/82754-alpha-26-pre-releaserelease-candidate-build-testing/page/10/#comment-508908) by @Gurken Khan.
Differential revision: https://code.wildfiregames.com/D4733
Comments by: @Stan, @wowgetoffyourcellphone