SECRETS: Use separate quotas for /kcm and /secrets hives
    
    This would differentiate between out-of-capacity errors for secrets and
    for KCM as they are two independent trees as far as sssd-secrets is
    concerned.
    
    The quotas for /kcm are also different in their defaults. For the /secrets
    hive, we presume a large amount of small secrets. For the /kcm hive, we
    presume a small amount of large secrets, because the secret is a ccache
    which contains multiple credentials.
    
    The operations are also passed in a struct quota from the local request
    context instead of local_context. The quota is assigned to the request
    context when the hive is selected.
    
    Reviewed-by: Simo Sorce <simo@redhat.com>
    Reviewed-by: Fabiano Fidêncio <fidencio@redhat.com>