Let the user know their input has been accepted

There are several areas of the UI that may take the system some time to complete. These include, but are not limited to:
Export of Products, Inventory, etc.
Duplicating products

Currently, there is no indication that the system has accepted the user's click. For instance, I recently tried to export the inventory for a site with 450 inventory items. There was no indication from the system that my click had succeeded. The export took nearly a minute to complete. During that time I had no clue if my click had registered.

Please add some sort of indicator for these tasks that shows the user that the action has been registered and pending.