Fix key rings being hinted as small key when keys are in their own dungeons

[GSKirox]

If a keyring is placed on a hinted spot but keys are in their own dungeons, it will be hinted as a Small key, because it will be treated as an Unshuffled dungeon item, and default back to its type name, which is currently SmallKey.

To reproduce, use a hint distribution that hints Skull Mask as always, put small keys in their own dungeons and plando a keyring on Skull Mask :

  "locations":                 {
    "Deku Theater Skull Mask":                              "Small Key Ring (Forest Temple)"
  }

The fix proposed is to give their own types to keyrings, and give it a generic type hint which will be used in this case.