Add an additional filter view, showing packages which were user picked

Add an additional filter view, showing packages which were user picked

Add an additional filter view, showing installed packages which were
selected for installation by the user, not installed as dependencies.

Future work:

Why is PickView::views is not an enum?

The view button would make more sense as a pop-up menu, allowing a specific
filter view to be directly selected, rather than cycling around the possible
filter views (and this situation is made worse by adding another filter
view)