HDRenderPipeline: Add SAMPLE_DEPTH_TEXTURE to our various API

ScriptableRenderPipeline/Core/ShaderLibrary/API/D3D11.hlsl

 #define SAMPLE_TEXTURECUBE_SHADOW(textureName, samplerName, coord4) textureName.SampleCmpLevelZero(samplerName, (coord3).xyz, (coord3).w)
 #define SAMPLE_TEXTURECUBE_ARRAY_SHADOW(textureName, samplerName, coord4, index) textureName.SampleCmpLevelZero(samplerName, float4((coord4).xyz, index), (coord4).w)
 
+#define SAMPLE_DEPTH_TEXTURE(textureName, samplerName, coord2) SAMPLE_TEXTURE2D(textureName, samplerName, coord2).r
+#define SAMPLE_DEPTH_TEXTURE_LOD(textureName, samplerName, coord2, lod) SAMPLE_TEXTURE2D_LOD(textureName, samplerName, coord2, lod).r
+
 #define TEXTURE2D_HALF TEXTURE2D
 #define TEXTURE2D_FLOAT TEXTURE2D
 #define TEXTURE3D_HALF TEXTURE3D

ScriptableRenderPipeline/Core/ShaderLibrary/API/Metal.hlsl

 #define SAMPLE_TEXTURECUBE_SHADOW(textureName, samplerName, coord4) textureName.SampleCmpLevelZero(samplerName, (coord3).xyz, (coord3).w)
 #define SAMPLE_TEXTURECUBE_ARRAY_SHADOW(textureName, samplerName, coord4, index) textureName.SampleCmpLevelZero(samplerName, float4((coord4).xyz, index), (coord4).w)
 
+#define SAMPLE_DEPTH_TEXTURE(textureName, samplerName, coord2) SAMPLE_TEXTURE2D(textureName, samplerName, coord2).r
+#define SAMPLE_DEPTH_TEXTURE_LOD(textureName, samplerName, coord2, lod) SAMPLE_TEXTURE2D_LOD(textureName, samplerName, coord2, lod).r
+
 #define TEXTURE2D_HALF TEXTURE2D
 #define TEXTURE2D_FLOAT TEXTURE2D
 #define TEXTURE3D_HALF TEXTURE3D

ScriptableRenderPipeline/Core/ShaderLibrary/API/PSSL.hlsl

 #define SAMPLE_TEXTURECUBE_SHADOW(textureName, samplerName, coord4) textureName.SampleCmpLevelZero(samplerName, (coord3).xyz, (coord3).w)
 #define SAMPLE_TEXTURECUBE_ARRAY_SHADOW(textureName, samplerName, coord4, index) textureName.SampleCmpLevelZero(samplerName, float4((coord4).xyz, index), (coord4).w)
 
+#define SAMPLE_DEPTH_TEXTURE(textureName, samplerName, coord2) SAMPLE_TEXTURE2D(textureName, samplerName, coord2).r
+#define SAMPLE_DEPTH_TEXTURE_LOD(textureName, samplerName, coord2, lod) SAMPLE_TEXTURE2D_LOD(textureName, samplerName, coord2, lod).r
+
 #define TEXTURE2D_HALF TEXTURE2D
 #define TEXTURE2D_FLOAT TEXTURE2D
 #define TEXTURE3D_HALF TEXTURE3D

ScriptableRenderPipeline/Core/ShaderLibrary/API/Vulkan.hlsl

 #define SAMPLE_TEXTURECUBE_SHADOW(textureName, samplerName, coord4) textureName.SampleCmpLevelZero(samplerName, (coord3).xyz, (coord3).w)
 #define SAMPLE_TEXTURECUBE_ARRAY_SHADOW(textureName, samplerName, coord4, index) textureName.SampleCmpLevelZero(samplerName, float4((coord4).xyz, index), (coord4).w)
 
+#define SAMPLE_DEPTH_TEXTURE(textureName, samplerName, coord2) SAMPLE_TEXTURE2D(textureName, samplerName, coord2).r
+#define SAMPLE_DEPTH_TEXTURE_LOD(textureName, samplerName, coord2, lod) SAMPLE_TEXTURE2D_LOD(textureName, samplerName, coord2, lod).r
+
 #define TEXTURE2D_HALF TEXTURE2D
 #define TEXTURE2D_FLOAT TEXTURE2D
 #define TEXTURE3D_HALF TEXTURE3D
 #define GATHER_TEXTURE2D(textureName, samplerName, coord2) textureName.Gather(samplerName, coord2)
 #define GATHER_TEXTURE2D_ARRAY(textureName, samplerName, coord2, index) textureName.Gather(samplerName, float3(coord2, index))
 #define GATHER_TEXTURECUBE(textureName, samplerName, coord3) textureName.Gather(samplerName, coord3)
-#define GATHER_TEXTURECUBE_ARRAY(textureName, samplerName, coord3, index) textureName.Gather(samplerName, float4(coord3, index))
+#define GATHER_TEXTURECUBE_ARRAY(textureName, samplerName, coord3, index) textureName.Gather(samplerName, float4(coord3, index))