Create docker-internal HAF-maintenance service

The following discussion from !392 (closed) should be addressed:

• @bwrona started a discussion:

  SUPERUSER and haf_administrators_group membership should be avoided here when external haf-maintenance process will be incorporated.

Also this can be solved then: !392 (comment 147499)

To create such service we should:

• create dedicated haf-maintainer role having proper permissions
• create some psql based scripts (usually just calling SQL procedures) using dedicated database role. Also such procedures should have set correct permissions to allow their execution only by haf-maintainer role
• discover some task-scheduler solution available for docker deployment. We can try: pg_cron or regular crond.