[Feature] Add a general progress bar about the conversion status (completed/total)

[nhtera]

Hi, I often compress many images at once and I am difficult to follow is that it has been completed all or not, I need scroll down and check all of them.

Can you add a general progress bar (the amount of completed processing/total)? And after completing all of them It's can show a message popup (optional).

This is an easy-to-use and effective program, thank you.