#452 - Collection View List Layout

With UITableView no longer being encouraged for use, we need to replace this behavior with UICollectionView. This is where UICollectionViewListLayout comes into play. Using this layout we can get the familiar table view appearance in plain and grouped styles (as well as additional styles to support sidebars on iPad and macOS). This includes support for sticky headers and footers, swipe actions, and other UITableView behaviors that we've come to rely on.