Project Search sort based on algorithmic score

The Project Search dropdown currently sorts by project.created_at, then project.id (taken from the performance bar. There is a param called order_by which if set to similarity will use a weighted algorithm to sort the projects returned: see the reorder_projects_with_similarity_order_support method in lib/api/groups.rb. This may be enough to fix the sorting of projects returned in the dropdown (and may be a frontend fix vs. a backend fix). I'm adding both labels and you can remove one of them once the MR is created.

current sql

/*application:web,correlation_id:01F7KWW7YB5A5JJF0SHE591PKS,endpoint_id:GET /api/:version/groups/:id/projects*/
SELECT
    "projects".*
FROM ((
        SELECT
            "projects".*
        FROM
            "projects"
        WHERE
            "projects"."namespace_id" = 9970
            AND (EXISTS (
                    SELECT
                        1
                    FROM
                        "project_authorizations"
                    WHERE
                        "project_authorizations"."user_id" = 5708766
                        AND (project_authorizations.project_id = projects.id))
                    OR projects.visibility_level IN (10, 20)))
        UNION (
            SELECT
                "projects".*
            FROM
                "projects"
                INNER JOIN "project_group_links" ON "projects"."id" = "project_group_links"."project_id"
            WHERE
                "project_group_links"."group_id" = 9970
                AND (EXISTS (
                        SELECT
                            1
                        FROM
                            "project_authorizations"
                        WHERE
                            "project_authorizations"."user_id" = 5708766
                            AND (project_authorizations.project_id = projects.id))
                        OR projects.visibility_level IN (10, 20)))) projects
    WHERE (("projects"."path" ILIKE '%test%'
            OR "projects"."name" ILIKE '%test%')
        OR "projects"."description" ILIKE '%test%')
AND "projects"."pending_delete" = FALSE
ORDER BY
    "projects"."created_at" DESC,
    "projects"."id" DESC
LIMIT 20 OFFSET 0

Plan

The Project search dropdown has two modes:

1. Any Group selected
2. Specific Group selected

I'll open an MR for each as the solutions are not identical, but both will rely upon sorting by similarity scopes that are exposed.