feat(webhook): provide grant id in outgoing payment events (#3335)

Author: dragosp1011

packages/backend/src/open_payments/payment/outgoing/model.ts

@@ -187,6 +187,10 @@ export class OutgoingPayment
     if (this.peerId) {
       data.peerId = this.peerId
     }
+
+    if (this.grantId) {
+      data.grantId = this.grantId
+    }
     return data
   }
 
@@ -274,6 +278,7 @@ export type PaymentData = Omit<OutgoingPaymentResponse, 'failed'> & {
   stateAttempts: number
   balance: string
   peerId?: string
+  grantId?: string
 }
 
 export const isOutgoingPaymentEventType = (

packages/backend/src/openapi/specs/webhooks.yaml

@@ -250,6 +250,9 @@ components:
             peerId:
               type: string
               format: uuid
+            grantId:
+              type: string
+              format: uuid
       additionalProperties: false
     walletAddressNotFound:
       required: