The matrices in the examples are given in an OpenGL-like coordinate system,
while a Vulkan-like coordinate system is used by wgpu. This was previously
partially corrected in the shader and by flipping the up axis of the camera,
but left the x-axis mirrored in the final result.
This change adds a conversion matrix to framework.rs that can be used
to convert from OpenGL to wgpu. This also allows us to set the
winding-order to counter-clockwise, which matches the ordering in the data.
