Added live refresh to admin UI

- Added lastLogin UI
- Added operational time

frontend/src/app/duration.pipe.spec.ts

@@ -0,0 +1,8 @@
+import { DurationPipe } from './duration.pipe';
+
+describe('DurationPipe', () => {
+  it('create an instance', () => {
+    const pipe = new DurationPipe();
+    expect(pipe).toBeTruthy();
+  });
+});