[idd] select linear RGB24 packing automatically

Replace the texture-shaped RGB24 output with a linear raw buffer and
keep its packing, damage translation, and buffer copies inside the
RGB24 effect.

Benchmark full-frame native and packed processing and retain the faster
path for each source format. Preserve logical damage rectangles for
client updates and alternating framebuffer repair.

Return compute outputs to COMMON for COPY queue handoff and refresh
cached framebuffer sizes when switching packed and native layouts.

idd/LGIdd/effect/CComputeEffect.h

@@ -37,6 +37,8 @@ namespace PostProcessUtil
 
   bool CreateDefaultTexture(const ComPtr<ID3D12Device3>& device,
     const D3D12_RESOURCE_DESC& desc, ComPtr<ID3D12Resource>& resource);
+  bool CreateDefaultBuffer(const ComPtr<ID3D12Device3>& device,
+    UINT64 size, ComPtr<ID3D12Resource>& resource);
 }
 
 class CComputeEffect : public CPostProcessEffect