Rethink sssd.conf and access.conf so do not change every time

Rethink how build sssd and access.conf (so does not change on every run).

We could probably reference the slurm.conf configs for examples of a minimal config for sssd.conf. The main thing that is more difficult is managing the list of simple_allowed_users and simple_allowed_groups. Perhaps we can build that list from all the various Ansible variables that populate them (join, sort, unique all entries) and then just ensure that one line via an ini file type module once.

I'm not sure how we'd improve access.conf.