pkp/pkp-lib#9829 Attempt to improve the search query performance

[jonasraoni]

The PR doesn't make miracles, some keywords might still be problematic, but it improved the situation.

[jonasraoni]

The biggest improvement came from this modification.
I'll create another issue to move the issue_id to a physical field, I've seen this CAST() in several places.

[jonasraoni]

The fix that we've adopted internally (as these updates are not enough) was to handicap the search even more, I basically replaced these lines:

ojs/classes/search/ArticleSearchDAO.php

Lines 89 to 98 in 44be719

	->groupBy('o.submission_id')
	->orderByDesc('count')
	->limit($limit)
	->select(
	'o.submission_id',
	DB::raw('MAX(s.context_id) AS journal_id'),
	DB::raw('MAX(i.date_published) AS i_pub'),
	DB::raw('MAX(p.date_published) AS s_pub'),
	DB::raw('COUNT(0) AS count')
	);

By:

            ->limit($limit * 4)
            ->select(
                'o.submission_id',
                DB::raw('s.context_id'),
                DB::raw('i.date_published AS i_pub'),
                DB::raw('p.date_published AS s_pub')
            );

        $q = DB::query()
            ->fromSub($q, 'x')
            ->groupBy('x.submission_id')
            ->orderByDesc('count')
            ->select(
                'x.submission_id',
                DB::raw('MAX(x.context_id) AS journal_id'),
                DB::raw('MAX(x.i_pub) AS i_pub'),
                DB::raw('MAX(x.s_pub) AS s_pub'),
                DB::raw('COUNT(0) AS count')
            );