LDAP: Move enum fields to id provider context
Move the enumeration-related struct members from "struct sdap_domain" to
"struct sdap_id_ctx". These fields are used by the ID provider
enumeration/cleanup tasks and other providers could also run enumeration
tasks.
Also use a talloc destructor to destroy the task as it is allocated in
the "struct sdap_id_ctx" context.
Signed-off-by: Samuel Cabrero <scabrero@suse.de>
Reviewed-by: Pavel Březina <pbrezina@redhat.com>