Expand method-specific parameters and status reasons documentation

The method-specific parameters page and status reasons page are now generated directly from the OpenAPI spec, ensuring descriptions, enum values, and payment method groupings stay in sync with the API. The status reason codes are now split by category (card scheme, merchant, terminal, voucher), each with full descriptions. Payment creation request parameters and response detail fields for all payment methods are now documented with accurate types and descriptions sourced from the spec.