Adds ability to re-add items to item list

When items are trashed, untrashed, favorited, or unfavorited, they will
reappear from any list they were hidden from before.
All counters on the nav bar change when trashing

Data properties contain project_id and favorite status, and the
appropriate counters change when trashing or untrashing an item.
Moves callbacks into the Callback object
Shortend Scrapped to S in many places