message: bench: Add more information to error messages
diff: #include <iterator>
  #include <memory>
  #include <sstream>
  +#include <string>
  namespace fs = std::filesystem;
  @@ -113,13 +114,24 @@ void validate_benchmark_case(benchmark::State& state, fizzy::test::WasmEngine& e
  if (benchmark_case.expected_result)
  {
  if (!result.value)
  - return state.SkipWithError("Missing result value");
  + {
  + const auto error_msg = "Missing result value, expected: " +
  + std::to_string(*benchmark_case.expected_result);
  + return state.SkipWithError(error_msg.c_str());
  + }
  else if (*result.value != *benchmark_case.expected_result)
  - return state.SkipWithError("Incorrect result");
  + {
  + const auto error_msg = "Incorrect result value, expected: " +
  + std::to_string(*benchmark_case.expected_result) +
  + ", got: " + std::to_string(*result.value);
  + return state.SkipWithError(error_msg.c_str());
  + }
  }
  else if (result.value)
  - return state.SkipWithError("Unexpected result");
  -
  + {
  + return state.SkipWithError(
  + ("Unexpected result value: " + std::to_string(*result.value)).c_str());
  + }
  const auto memory = engine.get_memory();
  if (memory.size() < benchmark_case.expected_memory.size())
  return state.SkipWithError("Result memory is shorter than expected");
  