fix: pass cancellation reason for seated event cancellations in API v2 (#24409)

* fix: pass cancellation reason for seated event cancellations in API v2

- Add cancellationReason field to CancelSeatedBookingInput_2024_08_13 type
- Update transformInputCancelSeatedBooking to use provided cancellationReason
- Fix pre-existing ESLint warnings (no-prototype-builtins) in isRescheduleSeatedBody and isCancelSeatedBody
- Fixes issue where API v2 throws 'cancellation reason required' error even when reason is provided
- Resolves validation error for hosts canceling seated events via API v2

Co-Authored-By: anik@cal.com <adhabal2002@gmail.com>

* Update input.service.ts

---------

Co-authored-by: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

apps/api/v2/src/ee/bookings/2024-08-13/services/input.service.ts

@@ -817,7 +817,7 @@ export class InputBookingsService_2024_08_13 {
     // for an individual person, so api users need to call booking by booking using uid + seatUid to cancel it.
     return {
       uid: bookingUid,
-      cancellationReason: "",
+      cancellationReason: inputBooking.cancellationReason || "",
       allRemainingBookings: false,
       seatReferenceUid: inputBooking.seatUid,
     };

packages/platform/types/bookings/2024-08-13/inputs/cancel-booking.input.ts

@@ -24,4 +24,9 @@ export class CancelSeatedBookingInput_2024_08_13 {
   })
   @IsString()
   seatUid!: string;
+
+  @IsString()
+  @IsOptional()
+  @ApiPropertyOptional({ example: "User requested cancellation" })
+  cancellationReason?: string;
 }