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-bar/dist/es2019/component.d.ts

@@ -0,0 +1,13 @@
+import * as React from 'react';
+import { GapMode } from './utils';
+export interface BodyScroll {
+    noRelative?: boolean;
+    noImportant?: boolean;
+    gapMode?: GapMode;
+}
+export declare const lockAttribute = "data-scroll-locked";
+export declare const useLockAttribute: () => void;
+/**
+ * Removes page scrollbar and blocks page scroll when mounted
+ */
+export declare const RemoveScrollBar: React.FC<BodyScroll>;