Support UUID Type for empty and notEmpty Functions

Why it matters

This feature allows users to check whether UUID values are empty (nil) directly using the empty and notEmpty functions. It simplifies filtering and conditional logic involving UUID columns by treating the nil UUID as empty, improving consistency with how other data types are handled.

How to use it

Use the existing empty or notEmpty functions with UUID type columns or values. For example:

SELECT * FROM table WHERE empty(uuid_column)

This query will select rows where the uuid_column contains the nil UUID (all zeros).