[e2e] Refactor and document our extension of existing Playwright API and RFE features (#5537)

e2e/helper/addNoneditableObject.js

@@ -0,0 +1,27 @@
+(function () {
+    document.addEventListener('DOMContentLoaded', () => {
+        const PERSISTENCE_KEY = 'persistence-tests';
+        const openmct = window.openmct;
+
+        openmct.objects.addRoot({
+            namespace: PERSISTENCE_KEY,
+            key: PERSISTENCE_KEY
+        });
+
+        openmct.objects.addProvider(PERSISTENCE_KEY, {
+            get(identifier) {
+                if (identifier.key !== PERSISTENCE_KEY) {
+                    return undefined;
+                } else {
+                    return Promise.resolve({
+                        identifier,
+                        type: 'folder',
+                        name: 'Persistence Testing',
+                        location: 'ROOT',
+                        composition: []
+                    });
+                }
+            }
+        });
+    });
+}());