[Collection] Serialization field for collection cards

{"ops":[{"insert":"Add a new field to the collection for every card to keep track of if they're a serialized version [X of N] copy of the card. \n\nSince Scryfall is unlikely to ever have all [X of N] unique images, we wouldn't bother tracking that, but what we can do is allow any card to have a number field where this value could be tracked (it could also be left blank for cards where this information isn't relevant). \n\neg: I own "},{"insert":{"card-link":"Sol Ring"}},{"insert":" 043 of 900 of the rings for mortal men sol ring.\n\n(Forgive if the picture isn't right, we don't allow selecting the version of a card inline 😅 maybe something to consider).\n"}]}