Enhance find_apartado_in_list Function for Efficiency

[christianoguedes]

The current implementation of find_apartado_in_list function aims to filter a list of strings based on a specific pattern related to 'apartado' numbers, ignoring leading zeros. While functional, this approach could potentially be optimized for better performance and readability. Specifically, the use of regex compilation inside the function might be reconsidered for cases with large datasets, and the process of stripping and lowering case for each item in the list could be streamlined. Additionally, ensuring the function's compatibility with various input formats and enhancing error handling could further improve its robustness and utility.