Let user enter payment details

[Jakob-SA]

• Choose between MobilePay, gift card and invoice
  • For gift card
    • user must enter amount, validate as number
    • user must enter gift card number, validate as number
    • if amount is larger than total amount, neither MobilePay nor invoice is available
  • For MobilePay, user must enter a phone number, validate as 8 digits
  • Invoice is only available, if billing address has company VAT number