Pluginize Webhooks and support Payouts (#5421)

Co-authored-by: d11n <mail@dennisreimann.de>

BTCPayServer/HostedServices/Webhooks/InvoiceWebhookDeliveryRequest.cs

@@ -0,0 +1,53 @@
+using System;
+using System.Globalization;
+using System.Threading.Tasks;
+using BTCPayServer.Client.Models;
+using BTCPayServer.Controllers;
+using BTCPayServer.Data;
+using BTCPayServer.Services.Invoices;
+using Newtonsoft.Json.Linq;
+using WebhookDeliveryData = BTCPayServer.Data.WebhookDeliveryData;
+
+namespace BTCPayServer.HostedServices.Webhooks;
+
+public class InvoiceWebhookDeliveryRequest : WebhookSender.WebhookDeliveryRequest
+{
+    public InvoiceEntity Invoice { get; }
+
+    public InvoiceWebhookDeliveryRequest(InvoiceEntity invoice, string webhookId, WebhookEvent webhookEvent,
+        WebhookDeliveryData delivery, WebhookBlob webhookBlob) : base(webhookId, webhookEvent, delivery, webhookBlob)
+    {
+        Invoice = invoice;
+    }
+
+    public override Task<SendEmailRequest> Interpolate(SendEmailRequest req,
+        UIStoresController.StoreEmailRule storeEmailRule)
+    {
+        if (storeEmailRule.CustomerEmail &&
+            MailboxAddressValidator.TryParse(Invoice.Metadata.BuyerEmail, out var bmb))
+        {
+            req.Email ??= string.Empty;
+            req.Email += $",{bmb}";
+        }
+
+        req.Subject = Interpolate(req.Subject);
+        req.Body = Interpolate(req.Body);
+        return Task.FromResult(req);
+    }
+
+    private string Interpolate(string str)
+    {
+        var res =  str.Replace("{Invoice.Id}", Invoice.Id)
+            .Replace("{Invoice.StoreId}", Invoice.StoreId)
+            .Replace("{Invoice.Price}", Invoice.Price.ToString(CultureInfo.InvariantCulture))
+            .Replace("{Invoice.Currency}", Invoice.Currency)
+            .Replace("{Invoice.Status}", Invoice.Status.ToString())
+            .Replace("{Invoice.AdditionalStatus}", Invoice.ExceptionStatus.ToString())
+            .Replace("{Invoice.OrderId}", Invoice.Metadata.OrderId);
+
+
+        res = InterpolateJsonField(str, "Invoice.Metadata", Invoice.Metadata.ToJObject());
+        return res;
+    }
+    
+}