ipareplica: Add support for hidden replica

The hidden replica support introduced some incompatible changes to replica
deployment. The methods find_providing_server and find_providing_serves
have been moved from ipaserver.install.service to ipaserver.masters.
Additionally the host_name argument for find_providing_server is a list
now. This breaks existing ipareplica Ansible modules ipareplica_prepare
and ipareplica_enable_ipa.