Feature: Rework alarm scheduling in iOS

### Description

Currently, due to the change in the implementation of alarm scheduling, the app is not at all working on the iOS platform. With this change in implementation, the app's dependency on the flutter foreground services was removed and replaced by the native code.

But it's only written for the Android platform yet and is to be done for the iOS platform. I would like to do this using the `Swift` language so that the alarm scheduling works for iOS as well.

_I would like to work on this issue, so please consider assigning it to me._

### Screenshots

https://github.com/CCExtractor/ultimate_alarm_clock/assets/92971894/4482b817-4088-4031-bafd-53a660d06f4c