Setting verification load using C-V2X Throttle Manager API

Please follow bellow steps to set the verificaton load

### 1. Create verification load callback function ###

static std::promise<telux::common::ErrorCode> gCallbackPromise;

// Callback function for Cv2xThrottleManager->setVerificationLoad()
static void cv2xsetVerificationLoadCallback(telux::common::ErrorCode error) {
    std::cout << "error=" << static_cast<int>(error) << std::endl;
    gCallbackPromise.set_value(error);
}

### 2. Create a initialization status callback function

bool cv2xTmStatusUpdated = false;
telux::common::ServiceStatus cv2xTmStatus =
    telux::common::ServiceStatus::SERVICE_UNAVAILABLE;
std::condition_variable cv;
std::mutex mtx;

auto statusCb = [&](telux::common::ServiceStatus status) {
    std::lock_guard<std::mutex> lock(mtx);
    cv2xTmStatusUpdated = true;
    cv2xTmStatus = status;
    cv.notify_all();
};

### 3. Get a handle to the ICv2xThrottleManager object ###

// Get handle to Cv2xThrottleManager
auto & cv2xFactory = Cv2xFactory::getInstance();
auto cv2xThrottleManager = cv2xFactory.getCv2xThrottleManager(statusCb);

### 4. Wait for throttle manager to complete initialization ###

std::unique_lock<std::mutex> lck(mtx);
cv.wait(lck, [&] { return cv2xTmStatusUpdated; });
if (telux::common::ServiceStatus::SERVICE_AVAILABLE !=
    cv2xTmStatus) {
    std::cout << "Error: failed to initialize Cv2xThrottleManager." << std::endl;
    return EXIT_FAILURE;
}

5. Set the verification load

cv2xThrottleManager->setVerificationLoad(load, cv2xsetVerificationLoadCallback);
if (telux::common::ErrorCode::SUCCESS != gCallbackPromise.get_future().get()) {
    std::cout << "Error : failed to set verification load" << std::endl;
    return EXIT_FAILURE;
} else {
    std::cout << "set verification load success" << std::endl;
}
gCallbackPromise = std::promise<telux::common::ErrorCode>();