Allow Use of groupArrayArray and groupUniqArrayArray as SimpleAggregateFunction

Why it matters

This feature enables users to leverage the groupArrayArray and groupUniqArrayArray functions within the SimpleAggregateFunction wrapper, allowing more flexible and composable aggregate function usage. It solves the limitation where these nested array aggregation functions could not previously be used as simple aggregate functions, enhancing the expressiveness and utility of aggregate queries.

How to use it

Users can now directly specify groupArrayArray and groupUniqArrayArray as aggregate functions inside SimpleAggregateFunction calls. For example:

SELECT SimpleAggregateFunction('groupArrayArray', column) FROM table;

or

SELECT SimpleAggregateFunction('groupUniqArrayArray', column) FROM table;