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/package.json

@@ -53,6 +53,7 @@
   "devDependencies": {
     "@babel/core": "7.6.4",
     "@babel/preset-env": "7.6.3",
+    "@babel/plugin-proposal-object-rest-spread": "7.13.8",
     "autoprefixer": "9.6.5",
     "caniuse-lite": "^1.0.30001037",
     "cssnano": "4.1.10",