improve responsiveness of the new project wizard finish action

Part of the feedback received from the usability study was that once you click the "Finish" button in the new project wizard the whole UI gets stuck after a while and it looks like the IDE died while it actually downloads maven deps of the project which is being created. We need to better indicate the steps being done while the user is waiting to prevent users from thinking their IDE got stuck. The progress bar should indicate running tasks as detailed as possible.