feat: redesign Exams List page to show submitted custom exams

- Added Custom Exams tab showing all exams from Generation page
- Displays title, module badges, duration, and status
- Added Create Exam button
- Kept Exam Sessions tab for institutional sessions
- Search filters across exams

Made-with: Cursor

node_modules/react-remove-scroll/dist/es2019/sidecar.js

@@ -0,0 +1,4 @@
+import { exportSidecar } from 'use-sidecar';
+import { RemoveScrollSideCar } from './SideEffect';
+import { effectCar } from './medium';
+export default exportSidecar(effectCar, RemoveScrollSideCar);