Summary:
Having React Native support every Apple platform is tough to achieve as it introduces many platform-specific ifdefs.

On the other side, maintaining an OOT platform fork is already a demanding job, so to make it easier I propose adding ifdefs for iOS-specific code. Thanks to this change, OOT platforms can focus on their OS-specific features while the core is also adding iOS-specific features behind ifdefs. Fortunately, **most of the code on Apple platforms can be shared** and this PR aims to introduce better support for this and to minimize OOT fork's surface.

In this example `RCTDeviceInfo.mm` has support for handling orientation changes and the availability of this feature across Apple OS looks as follows:

| Platform  | Support |
| ------------- | ------------- |
| macOS |  ❌  |
| tvOS |  ❌  |
| visionOS |  ❌  |
| iOS/iPadOS |  ✅  |

Here is a table from `TargetConditionals.h` header file which shows the coverage ...