LDAP: Add sdap_get_and_parse_generic_send
    
    Related:
        https://fedorahosted.org/sssd/ticket/2553
    
    So far we had a simple sdap_get_generic_send() request that uses the
    right defaults around the low-level sdap_get_generic_ext_send() request
    and calls the parser.
    
    This patch adds also sdap_get_and_parse_generic_send() that exposes all
    options that sdap_get_generic_ext_send() offers but also calls the
    parser.
    
    In this patch the function is not used at all.
    
    Reviewed-by: Pavel Březina <pbrezina@redhat.com>