macOS: non-native fullscreen window should restore as non-native fullscreen

Discussion: #3765

I think restoring a non-native fullscreen window should restore in the same state, since it's not as jarring as a regular fullscreen window. 

Reproduction:

```
fullscreen = true
macos-non-native-fullscreen = true
window-save-state = always
```

1. Open Ghostty
2. Quit Ghostty.
3. Open Ghostty