AnyNumeric really wants impl std::iter::Sum

[eeeebbbbrrrr]

It would be nice if pgrx implemented impl std::iter::Sum -- would make AnyNumeric easier to use here in plrust land.

[eeeebbbbrrrr]

well, would ya look at that: pgcentralfoundation/pgrx#1117

[eeeebbbbrrrr]

This got taken care of as part of #297

[v14.7][1841693] plrust=# create function sum_array(a numeric[]) returns numeric strict language plrust as $$ Ok(Some(a.into_iter().map(|e| e.unwrap()).sum()))
$$;
CREATE FUNCTION

[v14.7][1841693] plrust=# select sum_array(ARRAY[1, 2.0, 3.5]);
 sum_array 
-----------
       6.5
(1 row)