Move treat-as-file enum to better namespace

SabreTools.FileTypes/Enums.cs

@@ -1307,4 +1307,19 @@ namespace SabreTools.FileTypes
         TorrentZstd,
         TorrentZPAQ,
     }
+
+    /// <summary>
+    /// Determines what sort of files get externally hashed
+    /// </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,
+    }
 }