Description: - Create a reusable hook that uses TanStack Query to fetch country data. Tasks: - Create a useCountries hook. - Define a stable queryKey. - Connect the hook to the API function. - Return data, loading state, and error state. - Avoid duplicate or unnecessary requests. Acceptance Criteria: - Components can fetch countries through the hook. - Data is fetched when the application starts. - Loading and error states can be handled in the UI. - The same data is not fetched unnecessarily multiple times.