Expose bridge-safe pending, delivered, and settings snapshots from
UNUserNotificationCenter so apps can inspect local notification state
without native date objects or large payloads.
- Add getDeliveredNotifications and getNotificationSettings on iOS
- Harden getPendingNotifications with triggerTimestamp/triggerDateIso
- Always resolve with serializable values; omit userInfo from delivered
- Register new Capacitor methods and TypeScript definitions/web stubs