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

tests/RHI/D3D12/integration/minimal/CMakeLists.txt

@@ -39,6 +39,9 @@ add_custom_command(TARGET D3D12_Minimal POST_BUILD
     COMMAND ${CMAKE_COMMAND} -E copy_if_different
         ${CMAKE_CURRENT_SOURCE_DIR}/GT.ppm
         $<TARGET_FILE_DIR:D3D12_Minimal>/
+    COMMAND ${CMAKE_COMMAND} -E copy_if_different
+        ${ENGINE_ROOT_DIR}/third_party/renderdoc/renderdoc.dll
+        $<TARGET_FILE_DIR:D3D12_Minimal>/
 )
 
 add_test(NAME D3D12_Minimal_Integration