Fixed a mistake I made in the localization files thinking that "Expert" and "Impossible" entries in the localization strings were different, but no, the game just uses a separate string for lobby lists, using the "Impossible" one for Expert lobbies, despite it being an exact clone of the normal "Expert" string.

That probably made no sense, but who cares? You just want the beytah.

Added localization files to change difficulty names in most other places you'd see them. Not yet changed on the tab menu or vote pop-up.