Skip Mollie Orders API and only process through the Payments API

[anh-duc-le]

Is your feature request related to a problem? Please describe.
Our client's webshop sells digital products which makes up for at least 1/3 of the orders. A common feedback they receive from customers is the question

"Why do I have to fill in my billing address, city and postal code for a digital product?"

To accommodate for this we wanted to make the billing address optional for those who wish to receive a formal invoice with their order.

But this is not possible in the current Mollie Payment Service Provider which uses both the Orders and Payments API from Mollie to get Order insights in Mollie.
The https://docs.mollie.com/reference/v2/orders-api/create-order endpoint has a hard requirement on Billing Address information being filled.

Describe the solution you'd like
We would like the option of skipping the Orders API in the Mollie Payment Service Provider. Therefore enabling us to only collect billing address information when a customer wishes to receive an invoice.

Describe alternatives you've considered

I have discussed the option of simply sending dummy data to the Orders API from Mollie to meet the required data requirement, but this is a very dirty solution that we would not want to pursue and Mollie strongly recommends not to.

Additional context
The error in question:

MollieApiException: Unprocessable Entity - The following fields of the billingAddress are missing: streetAndNumber, postalCode, city
Mollie.Api.Client.BaseMollieClient.ProcessHttpResponseMessage<T>(HttpResponseMessage response)
Mollie.Api.Client.BaseMollieClient.SendHttpRequest<T>(HttpMethod httpMethod, string relativeUri, object data)
Mollie.Api.Client.BaseMollieClient.PostAsync<T>(string relativeUri, object data)
Mollie.Api.Client.OrderClient.CreateOrderAsync(OrderRequest orderRequest)
Umbraco.Commerce.PaymentProviders.Mollie.MollieOneTimePaymentProvider.GenerateFormAsync(PaymentProviderContext<MollieOneTimeSettings> ctx, CancellationToken cancellationToken)
Umbraco.Commerce.Common.Helpers.AsyncHelper+<>c__DisplayClass0_0<T>+<<RunSync>b__0>d.MoveNext()