问题5:更新食品防护屏的定义，并添加自助餐厅柜台、雕刻站、烹饪站、小学、移动自助柜台、多层和自助食品防护屏的定义。

Issue 5: Update the food shield definition and add definitions for cafeteria counter, carving station, cooking station, elementary school, mobile buffet counter, multiple tier, and self service food shields.