New scene method creates file(s) but doesn't save project

[Dgzt]

Describe the bug
If we create a new scene then the application creates scene file(s) in the project directory but doesn't save the project. And if we close the Mundus editor without project saving and reopen it then the new scene is missing but it's file is still in project directory.

To Reproduce
Steps to reproduce the behavior:

1. Click on 'Scenes' / Add scene" button
2. Add new scene
3. Close Mundus editor without project saving
4. Open Mundus editor
5. Click on "Scenes" menu
6. The new scene is missing

[Dgzt]

@JamesTKhan Should we save project if we add new scene?

[JamesTKhan]

That seems like the best approach to me.