Update code for CEF 124

[Scalibq]

In CEF 124, a new accelerated painting interface was introduced, using SHARED_NT handles now, via Direct3D 11.1. The code has been modified to work with the newer CEF release. As a quick-and-dirty patch, it makes the code render again, and it avoids the obvious exceptions and other issues. However, this may not be the preferred way to use the new interface. Currently the shared textures are used directly, but their lifetime may not be guaranteed outside the OnAcceleratedPaint()-callback, so it may be better to make a copy inside the OnAcceleratedPaint(), and then use the copy for rendering.