KH2: client bug fixes (ArchipelagoMW#1742)

Use item index instead of location and player to determine if the player should get the item.
Fixed getting stat increases on the title screen breaking stuff.
Changed local locations list from a list organized by world-id to a set.
Fixed the inventory slots to be the actual back of inventory.
Fixed recaching when not closing the client but switching slots .
Fixed getting a ability faster than the game so it dupes.
Removed verify location since it was never used.