Refactor pipeline state and render output abstractions

- Replace old pipeline enums/structs with new strongly-typed PipelineState and enums (ZTest, ZWrite, Cull, Blend, ColorWriteMask)
- Redesign pipeline keying: introduce 128-bit GraphicsPipelineKey, MaterialPipelineKey, and PassPipelineKey for robust PSO caching
- Replace IRenderTargetStrategy with IRenderOutput; add SwapChainRenderOutput and TextureRenderOutput
- Update renderer and window code to use new render output abstraction and handle viewport/scissor updates
- Make ShaderPass a readonly struct and Shader a struct; use ID-based pass lookup for efficiency
- Materials now support per-pass pipeline overrides with new keying
- Add defensive checks in D3D12CommandBuffer; update D3D12PipelineLibrary for new keying/state
- Move test shader to test.gsdef and update for new pipeline state syntax
- Remove obsolete files/interfaces and perform general code cleanups
- Update all usages and parsing logic for new pipeline state system

Ghost.Graphics/test.gsdef

@@ -0,0 +1,27 @@
+shader "MyShader/Standard"
+{
+    properties
+    {
+        float4 color = float4(1, 1, 1, 1);
+        tex2d texture1 = tex2d(black);
+        tex2d texture2 = tex2d(white);
+        tex2d texture3 = tex2d(grey);
+        tex2d texture4 = tex2d(normal);
+        sampler tex_sampler;
+    }
+
+    pass "Forward"
+    {
+        pipeline
+        {
+            ztest = disable;
+            zwrite = off;
+            cull = off;
+            blend = opaque;
+            color_mask = all;
+        }
+
+        ms("F:/csharp/GhostEngine/Ghost.Graphics/RenderPasses/ShaderCode.hlsl", "MSMain");
+        ps("F:/csharp/GhostEngine/Ghost.Graphics/RenderPasses/ShaderCode.hlsl", "PSMain");
+    }
+}