win32: add windowsapp which seems needed on MSVC

Author: jcelerier

cmake/libremidi.winmidi.cmake

@@ -66,3 +66,6 @@ target_include_directories(libremidi SYSTEM ${_public}
 target_compile_definitions(libremidi ${_public} LIBREMIDI_WINMIDI)
 set(LIBREMIDI_HAS_WINMIDI 1)
 target_link_libraries(libremidi INTERFACE RuntimeObject)
+if(MSVC)
+  target_link_libraries(libremidi ${_public} windowsapp)
+endif()

cmake/libremidi.winuwp.cmake

@@ -23,6 +23,7 @@ if(CPPWINRT_PATH)
   # We don't need /ZW option here (support for C++/CX)' as we use C++/WinRT
   if(MSVC)
     target_compile_options(libremidi ${_public} /EHsc)
+    target_link_libraries(libremidi ${_public} windowsapp)
   endif()
 else()
   message(STATUS "libremidi: Failed to find Windows SDK, UWP MIDI backend will not be available")