Add notification on longer processes

[Xewar313]

On some occasions (for example when processing a large file, or downloading it from a remote) the progress dialog takes a while to load. In these cases, users may want to change the window, but may still want to be notified of successfully completing the task.

I am proposing adding some notification when the process completes, similar to the one send by IntelliJ on test finish, when the browser window is not in focus.