[Desktop] Allow next/previous image when Info panel is opened (or "pin" as Info bar)

[ltguillaume]

At least for the desktop applications, it would be a vast improvement to allow browsing to the previous/next image while having the Info panel opened (and have it refresh automatically to expose the information of the currently viewed image).

In other words, it would be nice have the Info panel "pinned" as a sidebar once opened, so that you don't need to exit the Info panel, then open the previous/next image via Left/Right, then reopen the Info panel every single time.