Show payment method brand logos for Quickpay on checkout

[loevgaard]

Every surveyed plugin (official Mollie, PayPal, BitBag Adyen, CommerceWeavers Saferpay) renders brand logos on the checkout payment step; the official Quickpay modules for WooCommerce/PrestaShop likewise surface cards, MobilePay, Apple Pay, Google Pay, Klarna, Anyday, Vipps as recognizable brands. This plugin renders one generic radio labeled whatever the admin typed — for a Danish shop, a checkout without the MobilePay logo measurably undersells the payment method.

Proposal — the light version

Skip Mollie's heavy per-method entity model. The gateway config's payment_methods value already declares what the payment window will offer (e.g. creditcard, mobilepay, klarna-payments); derive the presentation from it:

• Bundle SVG logos for the common Quickpay payment method keys (cards, mobilepay, applepay, googlepay, klarna, anyday, vipps, …) and map payment_methods tokens → logos (unknown tokens simply render nothing)
• Render the logo row on the checkout payment-method choice for Quickpay methods via a form/template hook, mirroring how the plugin's existing form theme is wired (same pattern as the help_html workaround — Sylius' theme needs a scoped block)
• Pure presentation: no entities, no admin config beyond what payment_methods already says; shops can override the template/logos the normal Sylius way

Tasks

• Token → logo mapping + bundled assets (check Quickpay's brand-asset licensing for the logo files)
• Checkout template integration (shop template + form theme block), README note on overriding
• Handle the empty/unset payment_methods case (render nothing, as today)