Integrate RenderDoc frame capture into D3D12 minimal test

- Add SetDevice() and GetNumCaptures() methods to RenderDocCapture
- Fix initialization order: RenderDoc before D3D12, then SetDevice after
- Use nullptr for window param in StartFrameCapture/EndFrameCapture
- Add BeginCapture at frame 29, EndCapture at frame 30
- Set capture file path template to .\minimal_frame30
- Copy renderdoc.dll (26MB redistributable) to test output
- Engine/third_party/renderdoc/ now contains working renderdoc.dll

engine/include/XCEngine/Debug/RenderDocCapture.h

@@ -14,9 +14,11 @@ public:
 
     bool Initialize(void* device, void* window = nullptr);
     void Shutdown();
+    void SetDevice(void* device);
 
     bool IsLoaded() const { return m_isLoaded; }
     bool IsCapturing() const;
+    uint32_t GetNumCaptures() const;
 
     void BeginCapture(const char* title = nullptr);
     void EndCapture();