Add property to list page to remove table view header where appropriate

[simonmitchell]

In a lot of our apps we remove the tableViewHeader (Set it to near-zero frame) based on the first cell on ListPage this logic is normally fairly complex, but identical across all apps. This should be moved to a static property on ListPage which will allow us to set this before launch so ThunderCloud can handle all the logic required. Example of logic:

guard let firstRow = data.first?.rows.first, firstRow is ImageListItem || firstRow is HeaderListItem || firstRow is CollectionListItem || firstRow is SpotlightListItem else {
    return
}
tableView.tableHeaderView = UIView(frame: CGRect(x: 0, y: 0, width: 0.1, height: 0.1))