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-transition-group/esm/index.js

@@ -0,0 +1,6 @@
+export { default as CSSTransition } from './CSSTransition';
+export { default as ReplaceTransition } from './ReplaceTransition';
+export { default as SwitchTransition } from './SwitchTransition';
+export { default as TransitionGroup } from './TransitionGroup';
+export { default as Transition } from './Transition';
+export { default as config } from './config';