message: core: simplify int param conversion
  I don't think we have to translate it to a string to then convert it
  back to an int. We can just assume the bytes sent are float, and then
  cast them to int.
diff: @@ -1281,11 +1281,11 @@ bool MAVLinkParameters::ParamValue::set_as_same_type(const std::string& value_st
  if (std::get_if<float>(&_value)) {
  return std::get<float>(_value);
  } else if (std::get_if<int32_t>(&_value)) {
  - return std::stof(get_string());
  + return static_cast<int32_t>(std::get<float>(_value));
  } else if (std::get_if<int16_t>(&_value)) {
  - return std::stof(get_string());
  + return static_cast<int16_t>(std::get<float>(_value));
  } else if (std::get_if<int8_t>(&_value)) {
  - return std::stof(get_string());
  + return static_cast<int8_t>(std::get<float>(_value));
  } else {
  LogErr() << "Unknown type";
  assert(false);
  