server: exclude Local commands from RPC
    
    Local API commands are not supposed to be executed over RPC but only
    locally on the server. They are already excluded from API schema, exclude
    them also from RPC and `batch` and `json_metadata` commands.
    
    https://fedorahosted.org/freeipa/ticket/4739
    
    Reviewed-By: David Kupka <dkupka@redhat.com>