feat: add Polish translation

PR Summary

Addition of new translation file A new file called filament_shield.php has been added to the resources/lang/pl/ directory. This file is vital as it provides Polish language translations for various key components, such as labels for table columns, form fields, navigation directions, resource labels, different sections, and miscellaneous messages. This means our Polish-speaking users will find the application interface natively understandable, thereby improving their experience.