Reduce number of permission checks for subgroups in EpicsFinder [RUN ALL RSPEC] [RUN AS-IF-FOSS]

What does this MR do?

Skips checking of groups permission one-by-one in these cases:

• if user is not logged in - in that case we return just public groups
• if user is logged but not member of parent group - in that case we check if user is member of any related groups - if not, we return only public (and internal) groups

Related to #327454 (closed)

DB query

query plan (cold cache) which checks if there is any group (in related groups) which user is member of: https://console.postgres.ai/gitlab/gitlab-production-tunnel/sessions/3608/commands/12062 (depesz: https://explain.depesz.com/s/HhkV)

WITH RECURSIVE "base_and_descendants" AS (
                                            (SELECT "namespaces".*
                                             FROM "namespaces"
                                             WHERE "namespaces"."type" = 'Group'
                                               AND "namespaces"."id" = 9970)
                                          UNION
                                            (SELECT "namespaces".*
                                             FROM "namespaces",
                                                  "base_and_descendants"
                                             WHERE "namespaces"."type" = 'Group'
                                               AND "namespaces"."parent_id" = "base_and_descendants"."id"))
SELECT 1 AS one
FROM "base_and_descendants" AS "namespaces"
WHERE "namespaces"."id" IN
    (SELECT "namespaces"."id"
     FROM (
             (WITH "direct_groups" AS
                (SELECT "namespaces".*
                 FROM (
                         (SELECT "namespaces".*
                          FROM "namespaces"
                          INNER JOIN "members" ON "namespaces"."id" = "members"."source_id"
                          WHERE "members"."type" = 'GroupMember'
                            AND "members"."source_type" = 'Namespace'
                            AND "namespaces"."type" = 'Group'
                            AND "members"."user_id" = 1642716
                            AND "members"."requested_at" IS NULL
                            AND (access_level >= 10))
                       UNION
                         (SELECT namespaces.*
                          FROM "projects"
                          INNER JOIN "project_authorizations" ON "projects"."id" = "project_authorizations"."project_id"
                          INNER JOIN "namespaces" ON "namespaces"."id" = "projects"."namespace_id"
                          WHERE "project_authorizations"."user_id" = 1642716)) namespaces
                 WHERE "namespaces"."type" = 'Group') SELECT "namespaces".*
              FROM (
                      (SELECT "namespaces".*
                       FROM "direct_groups" "namespaces"
                       WHERE "namespaces"."type" = 'Group')
                    UNION
                      (SELECT "namespaces".*
                       FROM "namespaces"
                       INNER JOIN "group_group_links" ON "group_group_links"."shared_group_id" = "namespaces"."id"
                       WHERE "namespaces"."type" = 'Group'
                         AND "group_group_links"."shared_with_group_id" IN
                           (SELECT "namespaces"."id"
                            FROM "direct_groups" "namespaces"
                            WHERE "namespaces"."type" = 'Group'))) namespaces
              WHERE "namespaces"."type" = 'Group')
           UNION
             (SELECT "namespaces".*
              FROM "namespaces"
              INNER JOIN "members" ON "namespaces"."id" = "members"."source_id"
              WHERE "members"."type" = 'GroupMember'
                AND "members"."source_type" = 'Namespace'
                AND "namespaces"."type" = 'Group'
                AND "members"."user_id" = 1642716
                AND "members"."access_level" = 5)) namespaces
     WHERE "namespaces"."type" = 'Group')
LIMIT 1

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