message: Fix package of HandleResult, InitResult
diff: @@ -132,7 +132,7 @@ Integration Tests:
  - Remove all imports / use of `ContractResult`
  - You must specify `CosmosMsg::Native` type when calling
  `cosmwasm_vm::testing::{handle, init}`. You will want to
  - `use cosmwasm_vm::testing::{HandleResult, InitResult}` or
  + `use cosmwasm_std::{HandleResult, InitResult}` or
  `use cosmwasm_std::{HandleResponse, InitResponse}`. If you don't use custom
  native types, simply update calls as follows:
  - `let res = init(...)` => `let res: InitResult = init(...)`
  