HDrenderPipeline: Add depth offset support in debug view depth mode

Assets/ScriptableRenderPipeline/HDRenderPipeline/ShaderPass/ShaderPassDebugViewMaterial.hlsl

 
 #endif // TESSELLATION_ON
 			
-float4 Frag(PackedVaryingsToPS packedInput) : SV_Target
+void Frag(  PackedVaryingsToPS packedInput
+            , out float4 outColor : SV_Target
+            #ifdef _DEPTHOFFSET_ON
+            , out float outputDepth : SV_Depth
+            #endif
+            )
 {
     FragInputs input = UnpackVaryingsMeshToFragInputs(packedInput.vmesh);
 
 	if (!needLinearToSRGB)
 		result = SRGBToLinear(max(0, result));
 
-	return float4(result, 0.0);
+#ifdef _DEPTHOFFSET_ON
+    outputDepth = posInput.depthRaw;
+#endif
+
+    outColor = float4(result, 1.0);
 }
 

Assets/ScriptableRenderPipeline/ShaderLibrary/Common.hlsl

 void ApplyDepthOffsetPositionInput(float3 V, float depthOffsetVS, float4x4 viewProjMatrix, inout PositionInputs posInput)
 {
     posInput.depthVS    += depthOffsetVS;
-    posInput.positionWS -= depthOffsetVS * V;
+    posInput.positionWS += depthOffsetVS * -V; // opposite to V
 
     float4 positionCS = mul(viewProjMatrix, float4(posInput.positionWS, 1.0));
     posInput.depthRaw = positionCS.z / positionCS.w;