Find a way to represent cards in a maximized, generic sense for backwards compatibility

[scarletcs]

ScryfallCards.Any has been received relatively well, with one major setback: many existing systems depend on a more generic system where every card has every possible field present as optional.

We could just do without it, but it'd be helpful to people to provide a card type that has the following properties:

• All fields that exist on literally every layout will be guaranteed.
• All fields that MIGHT exist on SOME type will be present but possibly undefined.

The main hangup in this case is Reversible cards which omit several properties usually found present.