List payment service definitions

curl --request GET \
  --url https://api.{id}.gr4vy.app/payment-service-definitions \
  --header 'Authorization: Bearer <token>'

{
  "items": [
    {
      "id": "adyen-ideal",
      "type": "payment-service-definition",
      "display_name": "iDEAL",
      "method": "ideal",
      "fields": [
        {
          "key": "private_api_key",
          "display_name": "Private API key",
          "required": true,
          "format": "text",
          "secret": true
        }
      ],
      "reporting_fields": [
        {
          "key": "private_api_key",
          "display_name": "Private API key",
          "required": true,
          "format": "text",
          "secret": true
        }
      ],
      "supported_currencies": [
        "USD",
        "GBP",
        "EUR",
        "AUD"
      ],
      "supported_countries": "US",
      "mode": "card",
      "icon_url": "https://example.com/icons/adyen-ideal.svg",
      "supported_features": {},
      "required_checkout_fields": [
        {
          "required_fields": [
            "address.line1",
            "address.country",
            "address.city",
            "address.postal_code"
          ],
          "conditions": {
            "country": [
              "IN"
            ]
          }
        }
      ],
      "configuration": {
        "approval_ui_target": "any",
        "approval_ui_height": "100px",
        "approval_ui_width": "100px",
        "cart_items_limit": 100,
        "cart_items_required": true,
        "cart_items_should_match_amount": true
      }
    }
  ],
  "limit": 20,
  "next_cursor": "ZXhhbXBsZTE",
  "previous_cursor": "Xkjss7asS"
}