Create example app for Alive API

Depends-On: https://github.com/eclipse-score/lifecycle/pull/229

### What

Create a new example app that showcases the Alive API of the launch_manager.

### Acceptance Criteria (DoD)

New example app showcasing the alive API

### How

* Example app to be put under https://github.com/eclipse-score/lifecycle/tree/main/examples
* Create new folder cpp_supervised_app_simple for the app
* The app roughly looks like this:

```cpp
score::mw::lifecycle::Alive alive("instance");

// report Running state
// ...

// Report alive notifications
while(!exitRequested) {
alive.ReportAlive();
std::this_thread::sleep_for(std::chrono::milliseconds());
}

return 0;
}
```
- Maybe pass the via CLI (e.g. "-s ")
- Setup signal handling for handling SIGTERM
- Report Running state using lifecycle client
- Report alive notifications in a look until shutdown is requested
- Add the new example app to the existing demo configuration https://github.com/eclipse-score/lifecycle/blob/main/examples/demo_verification/lifecycle_demo_test.json and make sure everything still works