Gtk improvements

Squashed commit of the following:

commit 724c487ff5feca1e5ed1e0f006dd1c8e0112954b
Author: luxick <git@luxick.de>
Date:   Thu Mar 5 17:56:01 2020 +0100

    Reorder player columns

commit 5f56f73912122a42c3ee8fc64ed9760d18b9e706
Author: luxick <git@luxick.de>
Date:   Thu Mar 5 17:52:17 2020 +0100

    Data column constructor fix

commit fae314804b5bbe1be58ebdcb64690544bae76d1b
Author: luxick <git@luxick.de>
Date:   Thu Mar 5 17:51:39 2020 +0100

    Do not cast values in liststore to string

EstusShots.Gtk/Controls/BindableListControl.cs

@@ -84,7 +84,7 @@ namespace EstusShots.Gtk.Controls
                         $"Property '{column.PropertyName}' does not exist on Type '{item.GetType()}'");
                 var val = prop.GetValue(item);
                 if (column.Format != null) val = column.Format(val);
-                row.Add(val.ToString());
+                row.Add(val);
             }
 
             // The key value must be the first value in the row