cmake DU_PLATFORM_HAS_WINUWP_API examples

LadybirdBrowser/ladybird Meta/CMake/vcpkg/overlay-ports/icu/portfile.cmake :53

string(APPEND VCPKG_C_FLAGS " -DU_PLATFORM_HAS_WINUWP_API=1")

LadybirdBrowser/ladybird Meta/CMake/vcpkg/overlay-ports/icu/portfile.cmake :54

string(APPEND VCPKG_CXX_FLAGS " -DU_PLATFORM_HAS_WINUWP_API=1")