Added throwIf Function

Why it matters

The throwIf function allows users to raise errors conditionally during query execution, enabling better control over data validation and error handling within queries.

How to use it

Use the throwIf function by passing a condition as the first argument and an optional custom error message as the second. For example: SELECT throwIf(value < 0, 'Negative value not allowed') FROM table will throw an error if any value is negative.