Generate more optimal combined array lambda function emulations

[lukaseder]

jOOQ 3.20 added support for array lambda functions:

• Add support for lambda accepting array functions #16499

They can be emulated using correlated subqueries that UNNEST and ARRAY_AGG the array in order to use ordinary SQL to MAP (SELECT), FILTER (WHERE), etc.

When combining such array lambda functions, such as ARRAY_MAP(ARRAY_FILTER(...)), the current emulation isn't aware of the combination and produces such beasts (using kotlin):

select(array("1", "2", "3", "4").map { s -> s.cast(INTEGER) } .anyMatch {  i -> i.mod(2).ne(0) })

Produces this monster in PostgreSQL:

select (case
  when (
    select coalesce(
      array_agg(cast(e as int)),
      case
        when array['1', '2', '3', '4'] is not null then cast(array[] as int[])
      end
    )
    from unnest(array['1', '2', '3', '4']) as t (e)
  ) is not null then exists (
    select 1 as "one"
    from unnest((
      select coalesce(
        array_agg(cast(e as int)),
        case
          when array['1', '2', '3', '4'] is not null then cast(array[] as int[])
        end
      )
      from unnest(array['1', '2', '3', '4']) as t (e)
    )) as t (e)
    where mod(e, 2) <> '0'
  )
end)

When it should instead generate this:

select (case
  when array['1', '2', '3', '4'] is not null then exists (
    select 1 as "one"
    from unnest(array['1', '2', '3', '4']) as t (e)
    where mod(cast(e as int), 2) <> 0
  )
end)