Add a view to display the recently used items side by side with the main items view

The eventual goal is to make a "favorite items" view available to users that can be managed independent of the "recently used items", say through context menu options such as "add as favorite", "remove from favorites", etc.

The changes are kept to a minimum for simplicity (and the ItemsView class has been changed to be a bit over-arching). This is intentional and can be pulled out into a FavoriteItems view when more functionality is added.