Reduce view reuse and make view names better

[Coperh]

• AdyenPaymentView (session) and AdyenAdvancedPaymentView checkout
  • iDeal 2 redirect
  • get_context_data
  • CommonPaymentAdyenView -> CommonAdyenPaymentView or AdyenCommonPaymentView
  • rename to AdyenSessionPaymentView view?
• AdyenResponseView and AdyenDonationView
  • rename AdyenDonationView to AdyenResponseDonationView, deprecate old name ?
• rename AdyenOrderStatusView to something like AdyenStatusView, as donations can also use?