title: Check if card already added to PassKit library
body: <p>I am trying to add a banking card ("payment pass") to Wallet with PKAddPaymentPassRequest.</p>
  
  <p>So the question is, how can I query the pass library to check if my card (or  any other card) is already in the library? 
  For example, to show "Apple Pay enabled" checkmark on a card's UI in my app.</p>