Fix psql pager selection for wrapped expanded output

Hi,

While testing “[27da1a796] Improve psql's ability to select pager mode accurately”, I found that the pager doesn’t work for expanded wrapped mode. However, I realized that this is not a new problem introduced by 27da1a796, it didn’t work before 27da1a796 either. Instead, with 27da1a796, we are almost there to make it work.

27da1a796 introduces a new helper count_table_lines(), that takes a per-column-width array. For expanded mode (vertical mode), all columns use the same data width. So we can simply build such a width_wrap array, and move IsPagerNeeded() to after dwidth is computed. Then the pager works in expanded wrapped mode.

I tested with this procedure (making the terminal small with ~30 rows):
```
\pset pager on
\pset columns 25
\pset expanded on
\pset format wrapped
select g AS id, 'name_' || g AS name, repeat('x', g * 5) AS payload from generate_series(1, 10) AS g;
```
See the attached patch for details. I’m not going to add this to the v19 open items, as it’s not a v19-new bug.

Best regards,
--
Chao Li (Evan)
HighGo Software Co., Ltd.
https://www.highgo.com/