Add stable accessibilityOrder prop

[ya-nsh]

Summary:

Adds accessibilityOrder as the stable public prop name for configuring descendant accessibility focus order, while preserving experimental_accessibilityOrder as a backwards-compatible alias. This builds on the existing canary-gated native implementation and gives RNTester examples a public API surface for issue #49462.

Addresses #49462.

Changelog:

[GENERAL] [ADDED] - Add stable accessibilityOrder View prop.

Test Plan:

• yarn build-types
• yarn test-typescript
• yarn flow-check
• ./gradlew ktfmtCheck
• git diff --check

Manual RNTester verification is still needed with the accessibility order feature flag enabled.

[github-actions]

Warning

JavaScript API change detected

This PR commits an update to ReactNativeApi.d.ts, indicating a change to React Native's public JavaScript API.

• Please include a clear changelog message.
• This change will be subject to additional review.

This change was flagged as: POTENTIALLY_BREAKING