Shortcut for View Online

[mjthoraval]

When reviewing the metadata of some articles, I would like to open the URL quickly.
When an item is selected in the items list, I would like to use the shortcut Ctrl + Enter to open the URL instead of opening the PDF file.
It is already possible to do that from a right-click on the item or from the small icon on the right of the URL. But I would like to set it directly accessible from the keyboard. This is more convenient when navigating between items from the keyboard.
Related discussion in the Zotero Forums: https://forums.zotero.org/discussion/93419/opening-url-rather-than-pdf-shortcut/p1
Issue on Zutilo: wshanks/Zutilo#124