Add slang shaders for additional samples

shaders/slang/occlusionquery/simple.slang

@@ -0,0 +1,39 @@
+/* Copyright (c) 2025, Sascha Willems
+ *
+ * SPDX-License-Identifier: MIT
+ *
+ */
+
+struct VSInput
+{
+    float4 Pos;
+    float3 Color;
+};
+
+struct VSOutput
+{
+    float4 Pos : SV_POSITION;
+    float3 Color;
+};
+
+struct UBO
+{
+    float4x4 projection;
+    float4x4 view;
+    float4x4 model;
+};
+ConstantBuffer<UBO> ubo;
+
+[shader("vertex")]
+VSOutput vertexMain(VSInput input)
+{
+    VSOutput output;
+    output.Pos = mul(ubo.projection, mul(ubo.view, mul(ubo.model, float4(input.Pos.xyz, 1.0))));
+    return output;
+}
+
+[shader("fragment")]
+float4 fragmentMain()
+{
+    return float4(1.0, 1.0, 1.0, 1.0);
+}