Quest item filter should remember Inventory, not last Quest item

It is likely that you typed something like "heirloom" in your inventory filter to see if you have the heirloom, and if so went to turn it in. Thus the filter on the "Quest Item turn in" UI would be thinking ahead to match your last inventory search.

It's unlikely in most but not all situations, that you would want to have the previous quest item searched for be filled into the filter. After all, most of the time you have already turned it in, and so don't need to search for it again!