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/lodash/stubFalse.js

@@ -0,0 +1,18 @@
+/**
+ * This method returns `false`.
+ *
+ * @static
+ * @memberOf _
+ * @since 4.13.0
+ * @category Util
+ * @returns {boolean} Returns `false`.
+ * @example
+ *
+ * _.times(2, _.stubFalse);
+ * // => [false, false]
+ */
+function stubFalse() {
+  return false;
+}
+
+module.exports = stubFalse;