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/dom-helpers/cjs/removeClass.d.ts

@@ -0,0 +1,7 @@
+/**
+ * Removes a CSS class from a given element.
+ *
+ * @param element the element
+ * @param className the CSS class name
+ */
+export default function removeClass(element: Element | SVGElement, className: string): void;