Major Description
Add the flatten function that transforms an Array of Arrays column into an Array elements column. if the array structure contains more than two levels of nesting, the function removes one nesting level
Example:
flatten(array(array(1, 2, 3), array(3, 4, 5), array(6, 7, 8)) => [1,2,3,4,5,6,7,8,9]
