[Box] Support ref as prop

[ravisuhag]

Summary

The Box component has a comment stating it's an "old component just copied in v1 folder." It needs modernization and a clear decision on its future.

Improvements

1. Accept ref as a standard prop

The component uses ref?: React.RefObject<HTMLDivElement> as a regular prop but should follow the standard pattern used by all other components in the system, accepting ref via the component's props interface with proper typing (React.Ref<HTMLDivElement>).

Moved to Cross-Cutting Issues

The following items have been moved to cross-cutting issues that address them across all components:

• Clean up deprecated code (Clean up deprecated code, unused CSS, and legacy patterns #682)

[rohanchkrabrty]

Completed with #708