Perform a Google search and return formatted results. This function uses Google Custom Search API to search the web based on the provided query. It formats the results into a consistent structure and handles potential errors. Args: query (str): The search query string num_results (int, optional): Number of search results to return. Defaults to 5. Returns: Dict[str, Any]: A dictionary containing: - success (bool): Whether the search was successful - results (list): List of dictionaries with title, link, and snippet - total_results (str): Total number of results found (when successful) - error (str): Error message (when unsuccessful)