GC - Scratchcard Keyboard Controls

Adds Keyboard controls to GC scratchcards. Press enter to buy a scratchcard if you don't have any, select a scratchcard (the last one in the list if you have more than one), or scratch scratchcard. Then use 1-9 to scratch cells (1-3 are the top 3, 4-6 are the middle 3, 7-9 are the bottom 3). Press enter when done scratching to go back to the kiosk.