[feat] keep alive when simulated app gets closed

[JonasKruckenberg]

Describe the problem

When running Tauri inside the Xcode simulator (and I assume when running on a real device too) quitting the app quits the watcher and development server too. Restarting the app will just result in a blank screen bc the app remains in the simulators dock, but there won't be a dev-server backing the app anymore.

Describe the solution you'd like

This makes sense as it mirrors how Tauri works on the desktop, I would argue however that the lifetime of the watcher and development server should be tied to the lifetime of the simulator instead of the app (if that is technically possible). This has a few reasons:

1. The app icon remains in the simulators dock, intuitively a user assumes they can just click that icon again to re-launch the app
2. On mobile its common the kill an app to reset it's state to the initial one

Alternatives considered

No response

Additional context

No response