fix: add missing style mapping on flatlist

[maxencehenneron]

Summary

• The FlatList component was missing the className → style mapping in its StyledConfiguration, meaning className props on <FlatList> were silently ignored
• Added the missing mapping and a test to verify className correctly applies styles

Test plan

• Added test FlatList: className should map to style that verifies className="bg-red" produces the expected backgroundColor style
• Run yarn test to confirm all tests pass

[Copilot]

Pull request overview

This PR fixes a gap in the React Native CSS component wrappers where FlatList did not map className to the style prop, causing className on <FlatList> to be ignored. It adds the missing mapping and a regression test to ensure className produces the expected computed RN styles.

Changes:

• Add className: "style" to FlatList’s StyledConfiguration mapping.
• Add a Jest test asserting FlatList className results in the expected style prop.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
src/components/FlatList.tsx	Adds the missing className → style mapping so FlatList participates in the same styling behavior as other wrapped components.
src/tests/native/className-with-style.test.tsx	Adds a regression test ensuring FlatList className computes and applies styles to style.