Add generateRandom Table Function for Random Row Generation

Why it matters

This feature enables users to easily populate arbitrary test tables with random data, facilitating testing and development scenarios without needing real datasets.

How to use it

Use the generateRandom table function by specifying the desired schema to generate random rows. For example:

SELECT * FROM generateRandom('id Int32, name String', 1000)

This generates 1000 random rows with columns id and name.