make unknown items show up as "unknown" instead of "afterbirth"
make unknown items show up as "unknown" instead of "afterbirth"

viroulep/RebirthItemTracker,BrandonNowlin/RebirthItemTracker,Hyphen-ated/RebirthItemTracker,viroulep/RebirthItemTracker,Hyphen-ated/RebirthItemTrackerTest,sillypears/RebirthItemTracker,Zamiell/RebirthItemTracker,BrandonNowlin/RebirthItemTracker