"Search groups" in both Project & Group members doesn't allow to search for parent groups

What does this MR do and why?

As per #427782 (closed), we're unable to search for groups based on parent's name.

This MR solves the issue.

MR acceptance checklist

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Screenshots or screen recordings

Before	After

Query Plan

Before	After
SELECT "group_group_links".* FROM (SELECT DISTINCT ON (shared_with_group_id) * FROM "group_group_links" WHERE "group_group_links"."shared_group_id" = 10519 ORDER BY shared_with_group_id, group_access DESC, expires_at DESC, created_at ASC) group_group_links INNER JOIN "namespaces" ON "namespaces"."id" = "group_group_links"."shared_with_group_id" AND "namespaces"."type" = 'Group' WHERE "namespaces"."type" = 'Group' AND "namespaces"."type" != 'Project' AND ("namespaces"."path" ILIKE '%SEARCH%' OR "namespaces"."name" ILIKE '%SEARCH%')	SELECT "group_group_links".* FROM (SELECT DISTINCT ON (shared_with_group_id) * FROM "group_group_links" WHERE "group_group_links"."shared_group_id" = 10519 ORDER BY shared_with_group_id, group_access DESC, expires_at DESC, created_at ASC) group_group_links INNER JOIN "namespaces" ON "namespaces"."id" = "group_group_links"."shared_with_group_id" AND "namespaces"."type" = 'Group' WHERE "namespaces"."type" = 'Group' AND "namespaces"."type" != 'Project' AND "namespaces"."id" IN (SELECT "routes"."source_id" FROM "routes" WHERE "routes"."source_type" = 'Namespace' AND ("routes"."path" ILIKE '%SEARCH%' OR "routes"."name" ILIKE '%SEARCH%'))
https://postgres.ai/console/gitlab/gitlab-production-main/sessions/31235/commands/96980	https://postgres.ai/console/gitlab/gitlab-production-main/sessions/31235/commands/96979

How to set up and validate locally

1. Checkout the branch
2. Follow the steps-to-reproduce

Related to #427782 (closed)