Spinner not showing when clicking add new item and available canned scripts are not ready

If canned scripts are not available in a particular section when you click add new item (due to them being compiled), nothing will be shown. The scripts will appear once they are available but there is no indication we are waiting for them to be loaded which gives a bad user experience.

We should display a spinner when the user clicks the add new item button if we are waiting for the canned scripts to be loaded.