Create libraries for NFC reader APIs

### What is the problem or limitation you are having?

Toga doesn't support NFC readers.

### Describe the solution you'd like

Support NFC readers on Android and iOS.

### Describe alternatives you've considered

Using native platform APIs. But learning and implementing them separately can be time-consuming.

### Additional context

This was already suggested several times:

- https://discord.com/channels/836455665257021440/836455665257021443/1050878483678646392
- https://discord.com/channels/836455665257021440/836455665257021443/1158711066004574238
- https://discord.com/channels/836455665257021440/836455665257021443/1300540888833069087

For iOS it should be implemented here, I guess: https://github.com/beeware/toga/tree/main/iOS/src/toga_iOS/libs
And here for Android: https://github.com/beeware/toga/tree/main/android/src/toga_android/hardware

iOS documentation: https://developer.apple.com/documentation/corenfc
Android: https://developer.android.com/develop/connectivity/nfc/nfc
Web: https://developer.mozilla.org/en-US/docs/Web/API/Web_NFC_API

Start by reading the existing platform implementations in iOS/src/toga_iOS/libs and android/src/toga_android/hardware, then compare the Core NFC and Android NFC documentation linked in the issue. Define the shared Toga-facing behavior and platform-specific support for NFC readers; done means NFC readers work on both Android and iOS.

Written by the indexing model from the issue text.