Make separate category for 3rd pair and PPs under second pair

The filters in study mode automatically lump together 3rd pair and PPs under second pair (e.g., on AK7, QQ and 87s end up in the same bucket), but the behavior of these two hand classes are almost always in utter contrast to one another. Separating them in the filter tab (and every where else hand classes show up) would be most helpful.