factorize utility functions
added new constant in config.py
factorize presence_nick_conflict.py by using utility functions
factorize  iq_admin_get_affiliation.py  by using utility functions
factorized iq_admin_get_role.py  by using utility functions
factorized iq_admin_get_without_role_or_affiliation.py  by using utility functions
factorize remaining test using utility functions