Build a Signup Form component in React with validation and backend submission.

Requirements:

1. Include fields: Name, Email, Password, Confirm Password.
2. Validate inputs:
   • Name: required
   • Email: required and valid format
   • Password: required, minimum 6 characters
   • Confirm Password: should match Password
3. Display validation errors in real-time.
4. On successful validation, submit data to a mock API endpoint (e.g., POST to 'https://dummyjson.com/users').
5. Show success or error messages after submission.
6. Focus on functionality over styling.