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/date-fns/getDecade.d.ts

@@ -0,0 +1,22 @@
+/**
+ * @name getDecade
+ * @category Decade Helpers
+ * @summary Get the decade of the given date.
+ *
+ * @description
+ * Get the decade of the given date.
+ *
+ * @typeParam DateType - The `Date` type, the function operates on. Gets inferred from passed arguments. Allows to use extensions like [`UTCDate`](https://github.com/date-fns/utc).
+ *
+ * @param date - The given date
+ *
+ * @returns The year of decade
+ *
+ * @example
+ * // Which decade belongs 27 November 1942?
+ * const result = getDecade(new Date(1942, 10, 27))
+ * //=> 1940
+ */
+export declare function getDecade<DateType extends Date>(
+  date: DateType | number | string,
+): number;