role (str): The role of the user. Allowed values are "application admin", "global admin", "user".
first_name (str): The first name of the user. If not provided, the current first name will be used.
last_name (str): The last name of the user. If not provided, the current last name will be used.
200 OK: The user is updated successfully.
400 Bad Request: If versioning fails or invalid parameters are passed.
404 Not Found: If the user is not found.
500 Internal Server Error: On unhandled exceptions.