Summary

Migrates ErrorMessageList and ErrorMessageItem components in the shared filesystem storage plugin from class components to functional TypeScript components as part of the React 19 migration epic (#1774).

Changes Made

• Replace class component ErrorMessageList with a functional TypeScript component in list.tsx
• Replace class component ErrorMessageItem with a functional TypeScript component in item.tsx
• Convert class state (show, showDetails) to useState hooks
• Replace componentDidMount and UNSAFE_componentWillReceiveProps with useEffect
• Remove unused imports (policy, DefeatableLink) carried over from the original class components
• Add TypeScript interfaces for ErrorMessage, ErrorMessagesState, Match, History, and component props
• Add list.test.tsx with 14 unit tests covering rendering, loading state, table content, and close behaviour
• Add item.test.tsx with 9 unit tests covering row rendering and details toggle

Related Issues

• Issue: closes [Task](shared-file-system-storage-list): Migrate shared_filesystem_storage/components/error_messages/list.jsx #1965
• Epic: [EPIC](react-19): Upgrade to React 19 #1774

Screenshots (if applicable)

Checklist

• I have performed a self-review of my code.
• I have commented my code, particularly in hard-to-understand areas.
• I have added tests that prove my fix is effective or that my feature works.
• New and existing unit tests pass locally with my changes.
• I have made corresponding changes to the documentation (if applicable).
• My changes generate no new warnings or errors.