Package notifier sends desktop notifications. On Windows it uses the WinRT
COM API directly via go-toast/v2 to avoid the PowerShell window flash that
fyne's default implementation produces. On other platforms it delegates to
fyne.
New returns a platform-specific Notifier. The fyne app is used as the
fallback notifier on platforms where no native implementation is wired up,
and on Windows when the COM path fails to initialize.