Implement play/stop cap and shell music

test/imgui/examples/example_sdl3_sdlgpu3/build_win64.bat

@@ -0,0 +1,14 @@
+@REM Build for Visual Studio compiler. Run your copy of vcvars64.bat or vcvarsall.bat to setup command-line compiler.
+
+@set OUT_EXE=example_sdl3_sdlgpu3
+@set INCLUDES=/I..\.. /I..\..\backends /I%SDL3_DIR%\include
+@set SOURCES=main.cpp ..\..\backends\imgui_impl_sdl3.cpp ..\..\backends\imgui_impl_sdlgpu3.cpp ..\..\imgui*.cpp
+@set LIBS=/LIBPATH:%SDL3_DIR%\lib\x64 SDL3.lib shell32.lib
+
+@set OUT_DIR=Debug
+mkdir %OUT_DIR%
+cl /nologo /Zi /MD /utf-8 %INCLUDES% %SOURCES% /Fe%OUT_DIR%/%OUT_EXE%.exe /Fo%OUT_DIR%/ /link %LIBS% /subsystem:console
+
+@set OUT_DIR=Release
+@REM mkdir %OUT_DIR%
+@REM cl /nologo /Zi /MD /utf-8 /Ox /Oi %INCLUDES% %SOURCES% /Fe%OUT_DIR%/%OUT_EXE%.exe /Fo%OUT_DIR%/ /link %LIBS% /subsystem:console