message: Avoid unnecessary use of Binary in query request
diff: @@ -2,8 +2,8 @@ use serde::{de::DeserializeOwned, Serialize};
  use cosmwasm_std::testing::{MockQuerier as StdMockQuerier, MockQuerierCustomHandlerResult};
  use cosmwasm_std::{
  - to_binary, Binary, Coin, Empty, HumanAddr, Querier as _, QueryRequest, StdResult, SystemError,
  - SystemResult,
  + to_binary, to_vec, Binary, Coin, Empty, HumanAddr, Querier as _, QueryRequest, StdResult,
  + SystemError, SystemResult,
  };
  use crate::{FfiResult, GasInfo, Querier};
  @@ -75,7 +75,7 @@ impl MockQuerier {
  request: &QueryRequest<T>,
  ) -> FfiResult<SystemResult<StdResult<Binary>>> {
  // encode the request, then call raw_query
  - let request_binary = match to_binary(request) {
  + let request_binary = match to_vec(request) {
  Ok(raw) => raw,
  Err(err) => {
  let gas_info = GasInfo::with_externally_used(err.to_string().len() as u64);
  @@ -88,7 +88,7 @@ impl MockQuerier {
  );
  }
  };
  - self.query_raw(request_binary.as_slice())
  + self.query_raw(&request_binary)
  }
  }
  