Modernize to React 19 with functional components and add test coverage

[Copilot]

The component used React class components and lacked test infrastructure. Updated to React 19 with modern patterns and comprehensive capability tests.

Dependency updates

• React 16 → 19.0.0
• TypeScript 3.8.3 → 5.7.2
• Added Jest 29.7.0 + React Testing Library 16.1.0

Component modernization

• Converted TurkeyMap class component to functional component with hooks
• Replaced this.state with useState
• Replaced class methods with useCallback for memoization
• Fixed event handlers to use currentTarget.querySelector('path') instead of target for delegated events

Before:

export default class TurkeyMap extends Component<IProps, IState> {
  onMouseEnter = (event) => {
    (event.target as SVGGElement).style.fill = customStyle.hoverColor;
  }
}

After:

const TurkeyMap: React.FC<IProps> = ({ customStyle, ... }) => {
  const handleOnMouseEnter = useCallback((event) => {
    const path = event.currentTarget.querySelector('path');
    if (path) path.style.fill = customStyle.hoverColor;
  }, [customStyle.hoverColor]);
}

Test coverage

Added 26 tests covering:

• Rendering with default/custom props
• Mouse interactions (hover, click, enter, leave)
• Tooltip positioning and visibility
• Custom styling application
• City wrapper HOC pattern
• Re-render stability

All props maintain backward compatibility. Updated tsconfig.json to use react-jsx transform for React 19.

Original prompt

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This section details on the original issue you should resolve

<issue_title>Adapt Component for the newest ReactJS version</issue_title>
<issue_description>The component is quite old and needs to be adapted with the newest ReactJS version.

Also there needs to be capability tests implemented.</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes Adapt Component for the newest ReactJS version #20

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