Don't mutate argument inside function body

Fixes #13216.
Steps to reproduce
1. Require 'Magento_Checkout/js/model/address-converter' inside any JavaScript module.
2. Call quoteAddressToFormAddressData method with some address.
Expected result
1 .address.street should remain as an array. Eg. ['Sesame Street']

Author: vaaralav

app/code/Magento/Checkout/view/frontend/web/js/model/address-converter.js

@@ -72,20 +72,20 @@ define([
                 output = {},
                 streetObject;
 
+            $.each(addrs, function (key) {
+                if (addrs.hasOwnProperty(key) && !$.isFunction(addrs[key])) {
+                    output[self.toUnderscore(key)] = addrs[key];
+                }
+            });
+
             if ($.isArray(addrs.street)) {
                 streetObject = {};
                 addrs.street.forEach(function (value, index) {
                     streetObject[index] = value;
                 });
-                addrs.street = streetObject;
+                output.street = streetObject;
             }
 
-            $.each(addrs, function (key) {
-                if (addrs.hasOwnProperty(key) && !$.isFunction(addrs[key])) {
-                    output[self.toUnderscore(key)] = addrs[key];
-                }
-            });
-
             return output;
         },