Function run_statement_with_stats 

pub async fn run_statement_with_stats<T: StatementTransport>(
    cx: &Cx,
    client: &T,
    auth: AuthorizationDescriptor,
    request: SubmitStatementRequest,
    params: SubmitQueryParams,
    poll_plan: PollPlan,
) -> (StatementOutcome, DriverStats)

run_statement plus the poll/partition counts it consumed.