fix: preserve form data on API error and fix test cases (#338)

- Add temp storage utility (eventFormTempStorage.ts) to save/restore form data
- Implement error handling: close modal immediately, reopen on API failure with saved data
- Add event listeners in Calendar.tsx and EventDisplayPreview.tsx to reopen modals on error
- Fix calendar change logic in EventUpdateModal: use oldCalendar for update before move
- Update all test mocks to support .unwrap() method for Redux thunks
- Add sessionStorage.clear() in test beforeEach hooks
- Fix test timing issues with act() wrappers and increased timeouts
- Mock putEventAsync in TempUpdate test to ensure updateTempCalendar is called

- Fix update modal not reopening when API fails for recurring events (solo/all)
- Move update modal reopen logic from EventDisplayPreview to Calendar.tsx
- Use sessionStorage to persist update modal info across component unmounts
- Handle typeOfAction matching for recurring events (undefined vs solo/all)
- Fix error handling in updateEventInstanceAsync and updateSeriesAsync
- Ensure all API failures properly dispatch eventModalError event

__test__/features/Events/EventUpdateModal.test.tsx

@@ -13,6 +13,7 @@ describe("EventUpdateModal Timezone Handling", () => {
 
   beforeEach(() => {
     jest.clearAllMocks();
+    sessionStorage.clear();
   });
 
   const preloadedState = {