Add support for NaN and 0 values in QBars3D

While 0.f it is a valid QBars3DSerie value, 0.f is not rendered with a 3D bar (generating confusion with “no value” or “NaN”). In bars3drenderer_p.h, there is an internal property ‘bool m_noZeroInRange’, would it be possible to expose it to the user to allow drawing 0.f values?

Eventually, the following interface would be very useful:

const auto series1 = new QBar3DSeries{};
const auto data1 = new QBarDataRow{};
*data1 << std::numeric_limits<double>::signaling_NaN() << 4.f << 8.f << 16.f << 32.f;

Or something equivalent with Qt NaN API.