SDAP: Remove unused sdap_id_ctx from sdap_id_conn_cache_create Reviewed-by: Pavel Reichl <preichl@redhat.com>

LDAP: sdap_id_ctx might contain several connections With some LDAP server implementations, one server might provide different "views" of the identites on different ports. One example is the Active Directory Global catalog. The provider would contact different view depending on which operation it is performing and against which SSSD domain. At the same time, these views run on the same server, which means the same server options, enumeration, cleanup or Kerberos service should be used. So instead of using several different failover ports or several instances of sdap_id_ctx, this patch introduces a new "struct sdap_id_conn_ctx" that contains the connection cache to the particular view and an instance of "struct sdap_options" that contains the URI. No functional changes are present in this patch, currently all providers use a single connection. Multiple connections will be used later in the upcoming patches.

Pass sdap_id_ctx in sdap_id_op functions.

LDAP connection usage tracking, sharing and failover retry framework.