2022-June-16 - Prerelease - 2.6.921

Make static fields in UiContext non-static (#10656)

* Use resource loader from constructor instead of static variable

* Use field instead of passing loader around

* Wire ResourceLoader to PropertyFile class

* Remove remaining references to static ResourceLoader field

* Simplify method name and make variable final

* Make skinName non-static

* Make mapLocation non-static

* Make mapName non-static

* Clean up variables

* Implement manual getters and setters to fail fast on null

* Pass UiContext only where necessary

* Reset map name on shutdown