Drag and drop to an app on dock cycles through an inconvenient order if multiple windows of the app are open

## What Happened
When using drag and drop to an app that has multiple sessions/windows open from the dock, it cycles through an order that starts with the **most recently created** window and ends with the oldest created window.

## Expected Behavior
When cycling through the multiple sessions, the first window must be the **most recently opened** one and not the **most recently created** one.

https://user-images.githubusercontent.com/46734097/106033510-12630080-608f-11eb-91af-7c4e8588e5af.mp4

## Steps to Reproduce

1. Open multiple windows of an application.
2. Go to Files.
3. Drag a file and drop to the application using the dock.

## Platform Information

- Dell XPS 13 9380
- elementary OS 5.1.7 Hera
- Kernel: Linux 5.3.0-62-generic, GTK 3.22.30