`Scheme` property on various objects should be an enumeration, not a `string`

[iankemp-CapitalOnTap]

Event.Scheme

gocardless-dotnet/GoCardless/Resources/Event.cs

Line 239 in 97a32d1

public EventDetailsScheme? Scheme { get; set; }

is strongly-typed

gocardless-dotnet/GoCardless/Resources/Event.cs

Line 286 in 97a32d1

public enum EventDetailsScheme {

please can the below be similarly updated.

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Billing requests:

gocardless-dotnet/GoCardless/Services/BillingRequestService.cs

Line 924 in 97a32d1

public string Scheme { get; set; }

gocardless-dotnet/GoCardless/Services/BillingRequestService.cs

Line 1136 in 97a32d1

public string Scheme { get; set; }

gocardless-dotnet/GoCardless/Services/BillingRequestWithActionService.cs

Line 761 in 97a32d1

public string Scheme { get; set; }

gocardless-dotnet/GoCardless/Resources/BillingRequestWithAction.cs

Line 1030 in 97a32d1

public string Scheme { get; set; }

Mandates:

gocardless-dotnet/GoCardless/Services/MandateService.cs

Line 324 in 97a32d1

public string Scheme { get; set; }

gocardless-dotnet/GoCardless/Resources/Mandate.cs

Line 135 in 97a32d1

public string Scheme { get; set; }

Payments:

gocardless-dotnet/GoCardless/Services/PaymentService.cs

Line 554 in 97a32d1

public string Scheme { get; set; }

gocardless-dotnet/GoCardless/Resources/Payment.cs

Line 147 in 97a32d1

public string Scheme { get; set; }

[jamiecobbett]

Hi @iankemp-CapitalOnTap this is a result of how the fields are defined in our schema. I've added a ticket to our backlog to investigate whether they should all be defined as enums.

Worth noting that for the time being at least, they would be generated as independent enum types even though they might be equivalent. We're looking at that separately.