Physical deletion of projects and Spaces

In order to fix race conditions issues during the deletion of projects and spaces (another user/node is on the middle of another operation on the same project/space), we've introduced the logical deletion of projects and spaces.

Now it's time to finish these feature creating a timer that physical delete the project and space. This service should delete all the projects and spaces marked for deletion every minute (this should be parameterized in seconds).

Also, we need to show on spaces UI and projects UI that a project is marked for deletion. (these project and spaces should not be accessible for the user).