Extract the tests and refactor some of the methods.

Extract some of the ACI Tree functionalities, and decouple it from the
main source. Also - create some abstractions from the repeated code
around the enable/disable the schema children object create/edit/delete
functionalities, and also created the dialog wrappers for backup and
restore dialogs.

Reviewed by: Khushboo and Ashesh
Refactored by: Ashesh

web/regression/javascript/fake_model.js

@@ -0,0 +1,21 @@
+export class FakeModel {
+  constructor() {
+    this.values = {};
+  }
+
+  set(key, value) {
+    this.values[key] = value;
+  }
+
+  get(key) {
+    return this.values[key];
+  }
+
+  unset(key) {
+    delete this.values[key];
+  }
+
+  toJSON() {
+    return Object.assign({}, this.values);
+  }
+}