Blocks#597

d3d12 samples that depend onsamples/common were created before zgui/zmath and can be refactored:
#559 (comment)

samples/common holds thecsGenerateMipmaps incommon.hsl, which belongs inzd3d12 alongsidezd3d12.MipmapGenerator.

FrameStats should be moved tozd3d12.GraphicsContext to reach parity withzgpu.GraphicsContext

The following depend onsamples/common:

1. samples\audio_experiments
2. samples\audio_playback_test
3. samples\bindless
4. samples\directml_convolution_test
5. samples\mesh_shader_test
6. samples\rasterization
7. samples\simple_raytracer
8. samples\textured_quad
9. samples\triangle
10. samples\vector_graphics_test
11. samples\simple_openvr (common.hlsl only)