Replaced angular.extend with Utilities.extend (#10023)

* Replace angular.extend with Utilities.extend

* Replace more references of angular.extend with Utilities.extend

* Replace angular.extend

* Replace last reference of angular.extend except in Utilities itself

* Use spread operator

* Add spread operator

* Use existing format with empty destination object

* Configurate Babel to work with JS spread operator

* Use default for loose property which is "false"

* use alias for angular.extend - removes need for any other changes and makes multiple arguments easy

Co-authored-by: Nathan Woulfe <nathan@nathanw.com.au>

src/Umbraco.Web.UI.Client/.babelrc

@@ -6,5 +6,13 @@
                 "targets": "last 2 version, not dead, > 0.5%, not ie 11"
             }
         ]
+    ],
+    "plugins": [
+        [
+            "@babel/plugin-proposal-object-rest-spread",
+            {
+                "useBuiltIns": true
+            }
+        ]
     ]
 }