message: [Client] Rename arc_validator_verifier
  `arc_validator_verifier` seems like bad naming.
diff: @@ -137,7 +137,7 @@ impl GRPCClient {
  let req = UpdateToLatestLedgerRequest::new(0, requested_items.clone());
  debug!("get_with_proof with request: {:?}", req);
  let proto_req = req.clone().into_proto();
  - let arc_validator_verifier: Arc<ValidatorVerifier> = Arc::clone(&self.validator_verifier);
  + let validator_verifier = Arc::clone(&self.validator_verifier);
  let ret = self
  .client
  .update_to_latest_ledger_async_opt(&proto_req, Self::get_default_grpc_call_option())?
  @@ -146,7 +146,7 @@ impl GRPCClient {
  // the feature is available.
  let resp = UpdateToLatestLedgerResponse::from_proto(get_with_proof_resp?)?;
  - resp.verify(arc_validator_verifier, &req)?;
  + resp.verify(validator_verifier, &req)?;
  Ok(resp)
  });
  Ok(ret)
  