Fullscreen support for iOS

[cwist2]

First of all, thank you for this great library — it's been very helpful for building smooth and performant bottom sheets.

Feature request

I'd like to propose adding support for a fullscreen presentation mode on iOS, similar to what is already possible on Android.

Android	iOS

Use case

In some use cases (e.g., immersive forms, onboarding flows, or custom modals), displaying the TrueSheet in fullscreen on iOS would improve the user experience and visual consistency across platforms.

Expected behavior

When a certain prop (e.g., fullscreen or presentationStyle="fullscreen") is passed, the TrueSheet should cover the full height of the screen on iOS.

Thanks again for your work!