Chinese localization

Use InternationalizationProvider from @astryxdesign/core/i18n and the published zh-CN.generated.js messages. Set locale to zh-CN and pass messages={{'zh-CN': zhCN}}. Keep API identifiers unchanged. Test dates, long labels and text direction in the target application.

Pinned install:

npm install @astryxdesign/core@0.7.1 @astryxdesign/theme-neutral@0.7.1 @stylexjs/stylex@0.19.0