Implement array aggregate functions #7214

Is your feature request related to a problem or challenge?

Arrow DataFusion has a lot of aggregate functions for scalars and columns. We can compute an aggregate function with array by unnest funciton, but in my opinion it would be better to implement DuckDB methods to use different list_ aggregate functions.

List

The full list of array aggregate functions:

General:

• array_avg (alias: list_avg)
• array_bit_and (alias: list_bit_and)
• array_bit_or (alias: list_bit_or)
• array_bit_xor (alias: list_bit_xor)
• array_bool_and (alias: list_bool_and)
• array_bool_or (alias: list_bool_or)
• array_count (alias: list_count)
• array_max (alias: list_max)
• array_mean (alias: list_mean)
• array_median (alias: list_median)
• array_min (alias: list_min)
• array_sum (alias: list_sum)

Statistical:

• array_stddev (alias: list_stddev)
• array_stddev_pop (alias: list_stddev_pop)
• array_stddev_samp (alias: list_stddev_samp)
• array_var (alias: list_var)
• array_var_pop (alias: list_var_pop)
• array_var_samp (alias: list_var_samp)

Approximate:

• array_approx_distinct (alias: list_approx_distinct)
• array_approx_median (alias: list_approx_median)

Describe the solution you'd like

No response

Describe alternatives you've considered

No response

Additional context

DuckDB documentation: https://duckdb.org/docs/sql/functions/nested;
Apache Arrow DataFusion aggregate functions: https://arrow.apache.org/datafusion/user-guide/sql/aggregate_functions.html