Improve "Add New Card" form

Allow users to only add last 4 digits instead of all 16 digits. Currently the app asks for all 16 digits of the card, which is insane. Instead give users option to add only last 4 digits until they decide to trust the app.

Allow users to not provide CVV/PIN, it’s optional in the model already, but the UI enforces it to be mandatory.

Allow users to choose CardType and CardProvider in the UI, auto-update based on the number if it’s possible, but allow users to override it. Currently it auto-decides card type and provider behind the scenes.