fix(local-notifications): Delete delivered notifications on iOS

[jkatins]

When deleting notifications with cancel() or cancelAll(), on Android scheduled and delivered notifications are deleted. On iOS, only scheduled notifications are deleted. Notifications that are already delivered remain. With the latest plugin version 6.3.0 there's no way to delete them.

This PR makes cancel() and cancelAll() work the same on both platforms by deleting delivered notifications on iOS too.