Title: #5450: kcm: add support for kerberos tgt renewals
Also what do we need the renew hash table for? I don't see where
you take advantage of it? You always call `kcm_ccdb_renew_init` from
`kcm_renew_tgt_timer_handler` so you always iterate over all cached credentials before you
attempt to renew it. What was the intention here?
i was using krb5 renewals as a starting point for my code, ``add_tgt_to_renew_table`` uses
the hash table. Is it better to just use an array of ``renew_data`` structures?
``kcm_renew_all_tgts`` is where we retrieve the hash table entries to check for
See the full comment at https://github.com/SSSD/sssd/pull/5450#issuecomment-811149203