Fix productivity analytics listing with multiple labels

What does this MR do?

Fixes the bug with multiple labels listing on Productivity analytics page

Performance comparison

Old query for 3 months data as benchmark: https://explain.depesz.com/s/cKvj

SELECT DATE_PART('day', merge_request_metrics.merged_at - merge_requests.created_at) as metric, count(*) as mr_count FROM "merge_requests" INNER JOIN "projects" ON "projects"."id" = "merge_requests"."target_project_id" INNER JOIN "merge_request_metrics" ON "merge_request_metrics"."merge_request_id" = "merge_requests"."id" LEFT JOIN project_features ON projects.id = project_features.project_id WHERE "projects"."namespace_id" IN (WITH RECURSIVE "base_and_descendants" AS ((SELECT "namespaces".* FROM "namespaces" WHERE "namespaces"."type" IN ('Group') AND "namespaces"."id" = 9970)
UNION
(SELECT "namespaces".* FROM "namespaces", "base_and_descendants" WHERE "namespaces"."type" IN ('Group') AND "namespaces"."parent_id" = "base_and_descendants"."id")) SELECT "namespaces"."id" FROM "base_and_descendants" AS "namespaces") AND (EXISTS (SELECT 1 FROM "project_authorizations" WHERE "project_authorizations"."user_id" = 1 AND (project_authorizations.project_id = projects.id)) OR projects.visibility_level IN (0,10,20)) AND ("project_features"."merge_requests_access_level" > 0 OR "project_features"."merge_requests_access_level" IS NULL) AND ("merge_requests"."state_id" IN (3)) AND "merge_request_metrics"."merged_at" >= '2019-10-05 14:34:33' GROUP BY DATE_PART('day', merge_request_metrics.merged_at - merge_requests.created_at)

Planning time	:	3.175 ms
Execution time	:	493.188 ms

New query for 3 months data: https://explain.depesz.com/s/tfJA

SELECT DATE_PART('day', merge_request_metrics.merged_at - merge_requests.created_at) as metric, count(*) as mr_count FROM "merge_request_metrics" INNER JOIN "merge_requests" ON "merge_requests"."id" = "merge_request_metrics"."merge_request_id" WHERE "merge_request_metrics"."merge_request_id" IN (SELECT "merge_requests"."id" FROM "merge_requests" INNER JOIN "projects" ON "projects"."id" = "merge_requests"."target_project_id" INNER JOIN "merge_request_metrics" ON "merge_request_metrics"."merge_request_id" = "merge_requests"."id" LEFT JOIN project_features ON projects.id = project_features.project_id WHERE "projects"."namespace_id" IN (WITH RECURSIVE "base_and_descendants" AS ((SELECT "namespaces".* FROM "namespaces" WHERE "namespaces"."type" IN ('Group') AND "namespaces"."id" = 9970)
UNION
(SELECT "namespaces".* FROM "namespaces", "base_and_descendants" WHERE "namespaces"."type" IN ('Group') AND "namespaces"."parent_id" = "base_and_descendants"."id")) SELECT "namespaces"."id" FROM "base_and_descendants" AS "namespaces") AND "projects"."visibility_level" = 20 AND ("project_features"."merge_requests_access_level" IN (20, 30) OR "project_features"."merge_requests_access_level" IS NULL) AND ("merge_requests"."state_id" IN (3)) AND "merge_request_metrics"."merged_at" >= '2019-08-01 09:42:14' ORDER BY "merge_requests"."id" DESC) GROUP BY DATE_PART('day', merge_request_metrics.merged_at - merge_requests.created_at)

Planning time	:	4.291 ms
Execution time	:	595.736 ms

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation created/updated or follow-up review issue created
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team

Closes #33182 (closed)