Windows startup status

[veto9292]

Instead of the current isEnabled method, use a stream so that by listening to it, when the status changes outside the app, the status inside the app gets updated.

[kamilkarp]

@veto9292 I've actually needed that feature in one of my app. https://github.com/kamilkarp/launch_at_startup/tree/feat/observe-external-changes-with-reg-observe-plugin

It uses custom plugin for registry observation and the stream feature is only implemented for windows. Just remember that I haven't really looked at it for quite a while so it's not updated etc.

Stream<bool> _observeAutostartEnabled() {
    return Rx.concat([
      Rx.fromCallable(launchAtStartup.isEnabled),
      launchAtStartup.observeIsEnabled(),
    ]);
  }

[veto9292]

Thanks
I have temporarily used a timer to sync external changes with the app.
Since Windows is the most used Desktop platform, the problem is solved to some extent, but I have used this plugin for all Desktop platforms.