Move TreatAsFile up a library layer

SabreTools.DatItems/Enums.cs

@@ -3,6 +3,21 @@ using SabreTools.Core;
 
 namespace SabreTools.DatItems
 {
+    /// <summary>
+    /// Determines what sort of files only use external hashes
+    /// </summary>
+    /// TODO: Can FileType be used instead?
+    [Flags]
+    public enum TreatAsFile
+    {
+        CHD = 1 << 0,
+        Archive = 1 << 1,
+        AaruFormat = 1 << 2,
+
+        NonArchive = CHD | AaruFormat,
+        All = CHD | Archive | AaruFormat,
+    }
+
     /// <summary>
     /// Determine the chip type
     /// </summary>