Base: Rename and update card backs

CobyCat has very kindly remastered their card backs to fit the new card
back dimensions of 72 x 102px with 3px rounded corners. This gives
cards 3px of inner border which looks much neater.

Also, all card names have been capitalized and the suffix '-deck'
removed to improve their appearance in GamesSettings.

Co-authored-by: Tom L <lemtom@users.noreply.github.com>