Added a method that sets the loader to shipping rates after changing the post code

Author: rostilos

app/code/Magento/Checkout/view/frontend/web/js/model/shipping-rates-validator.js

@@ -17,6 +17,7 @@ define([
     'mage/translate',
     'uiRegistry',
     'Magento_Checkout/js/model/shipping-address/form-popup-state',
+    'Magento_Checkout/js/model/shipping-service',
     'Magento_Checkout/js/model/quote'
 ], function (
     $,
@@ -28,7 +29,8 @@ define([
     defaultValidator,
     $t,
     uiRegistry,
-    formPopUpState
+    formPopUpState,
+    shippingService
 ) {
     'use strict';
 
@@ -146,6 +148,7 @@ define([
                     }, delay);
 
                     if (!formPopUpState.isVisible()) {
+                        shippingService.isLoading(true);
                         clearTimeout(self.validateAddressTimeout);
                         self.validateAddressTimeout = setTimeout(function () {
                             self.validateFields();