Issue a virtual card via Marqeta: create card product then provision virtual card

Steps

1. Authenticate using HTTP Basic Auth with your application token as username and admin access token as password against the Marqeta sandbox or production base URL
2. Create a Card Product: POST /cardproducts with a config object specifying fulfillment (type: 'VIRTUAL_PAN'), card_life_cycle (activate_upon_issue: true or false), controls (spending limits, velocity), and a unique name and token
3. Create a User if not already created: POST /users with first_name, last_name, email, and any required KYC fields; receive a user token
4. Create a GPA Order to fund the user's account: POST /gpaorders with user_token, amount, currency_code, and funding_source_token
5. Create the virtual card: POST /cards with user_token, card_product_token, and optionally fulfillment.shipping fields; receive the card token and, if activate_upon_issue is true, a pan, cvv_number, and expiration