fix(iOS, Stack): handle icon rendering modes for bar button items

[kligarski]

Description

Previously, both imageSource and templateSource were handled in the same way (relying on UIKit's automatic rendering mode). To match API and current convention from Bottom Tabs, this PR handles rendering modes separately.

Simulator.Screen.Recording.-.iPhone.16.Pro.-.2025-10-27.at.14.04.35.mov

Changes

• handle imageSource and templateSource separately
• update test screen to match react-navigation API

Test code and steps to reproduce

Run BarButtonItems test screen. Open Icon Button example. Change tinted in button configuration from false to true.

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

[kkafar]

Looks good thank you!

[kkafar]

I feel like we need additional PR here, that will refactor out this code & share it between here & header config.

[kkafar]

Created ticket for this: https://github.com/software-mansion/react-native-screens-labs/issues/525