RHI: Remove无效的动态状态方法 - SetDepthStencilState/SetBlendState

重构原因：
- D3D12 PSO是不可变的，SetDepthStencilState/SetBlendState调用原本就是空实现(TODO)
- 这些方法在D3D12中完全无效，是死代码

移除的方法：
- SetDepthStencilState(const DepthStencilState&) - D3D12空实现，OpenGL直接调用GL函数
- SetBlendState(const BlendState&) - D3D12只设置BlendFactor其他忽略，OpenGL直接调用GL函数

保留的真正动态状态：
- SetViewport/SetViewports
- SetScissorRect/SetScissorRects
- SetStencilRef (D3D12动态状态)
- SetBlendFactor (D3D12动态状态)

注：PrimitiveTopology保留在CommandList，因为D3D12允许动态改变topology type

测试状态：150个RHI单元测试全部通过，8个集成测试全部通过

tests/RHI/OpenGL/unit/test_command_list.cpp

@@ -147,36 +147,6 @@ TEST_F(OpenGLTestFixture, CommandList_SetPrimitiveTopology) {
     EXPECT_EQ(error, GL_NO_ERROR);
 }
 
-TEST_F(OpenGLTestFixture, CommandList_SetDepthStencilState) {
-    OpenGLCommandList cmdList;
-    
-    DepthStencilState state = {};
-    state.depthEnable = true;
-    state.depthWriteMask = true;
-    state.depthFunc = ComparisonFunc::Less;
-    
-    cmdList.SetDepthStencilState(state);
-    
-    GLint depthTest = 0;
-    glGetIntegerv(GL_DEPTH_TEST, &depthTest);
-    EXPECT_EQ(depthTest, 1);
-}
-
-TEST_F(OpenGLTestFixture, CommandList_SetBlendState) {
-    OpenGLCommandList cmdList;
-    
-    BlendState state = {};
-    state.renderTargets[0].blendEnable = true;
-    state.renderTargets[0].srcBlend = BlendFactor::SrcAlpha;
-    state.renderTargets[0].dstBlend = BlendFactor::InvSrcAlpha;
-    
-    cmdList.SetBlendState(state);
-    
-    GLint blend = 0;
-    glGetIntegerv(GL_BLEND, &blend);
-    EXPECT_EQ(blend, 1);
-}
-
 TEST_F(OpenGLTestFixture, CommandList_SetBlendFactor) {
     OpenGLCommandList cmdList;