fix(iOS, Stack v4): add systemDefault option to autoCapitalize prop in SearchBar

[kligarski]

Description

Ensures consistent default behavior for autoCapitalize prop in SearchBar.

This will require changes in react-navigation's docs (https://github.com/software-mansion/react-native-screens-labs/issues/470).

Before

Prior to this PR, changing autoCapitalize to none on Fabric required changing the value to something else and then changing it back to none as none was the default value in Fabric spec file for SearchBar (controller would not get the updated value and used UIKit default - sentences).

autoCapitalize_before_iOS_Fabric.mov

After

In this PR, bug described in section above is fixed. Consistent behavior across platforms and architectures is ensured.

autoCapitalize_after_iOS_Fabric.mov

systemDefault option allows correct handling of different search input default behaviors on Android and iOS:

• on Android, default behavior is the same as none,
• on iOS, default behavior is the same as sentences.

Changes

• add systemDefault to autoCapitalize in SearchBar
• handle systemDefault on both platforms and both architectures
• parse JS autoCapitalize prop by mapping undefined to systemDefault to ensure consistent behavior between Paper and Fabric: on Paper, setter does not run if we pass undefined as the value of the prop whereas on Fabric, default value of systemDefault is used.

Test code and steps to reproduce

Run Test758 with commented-out search bar options. Add autoCapitalize: 'none' and verify correct behavior.

Checklist

• Included code example that can be used to test this change
• Updated TS types
• Updated documentation:
  • https://github.com/software-mansion/react-native-screens/blob/main/guides/GUIDE_FOR_LIBRARY_AUTHORS.md
  • https://github.com/software-mansion/react-native-screens/blob/main/native-stack/README.md
  • https://github.com/software-mansion/react-native-screens/blob/main/src/types.tsx
  • https://github.com/software-mansion/react-native-screens/blob/main/src/native-stack/types.tsx
• Ensured that CI passes

[kmichalikk]

nit: I'd say something like decorateAutocapitalizeWithSystemDefaultIfNeeded would sound better?

[kligarski]

I assumed that there might be more props that will require this kind of handling (but at the moment I'm not sure if there will be more) and wanted to use only one function for all of them so that it's easier to delete it in the future when we drop support for legacy architecture.

Also, isn't decorate a little bit too much for simple if (value === undefined) return "systemDefault"?

I'm open for suggestions here.

[kkafar]

Good catch. The code looks sensible. Thank you.