adds multi payment webhook event types

Author: MasterSlave

src/main/java/io/craftgate/model/WebhookEventType.java

@@ -14,5 +14,8 @@ public enum WebhookEventType {
     WALLET_TX_CREATED,
     BNPL_NOTIFICATION,
     BANK_ACCOUNT_TRACKING_RECORD,
-    BKM_EXPRESS_PAYMENT_NOTIFICATION
+    BKM_EXPRESS_PAYMENT_NOTIFICATION,
+
+    MULTI_PAYMENT_COMPLETED,
+    MULTI_PAYMENT_EXPIRED
 }