Add and use Endianness enum

SabreTools.Library/DatItems/Enums.cs

@@ -50,6 +50,22 @@ namespace SabreTools.Library.DatItems
         External = 1 << 3,
     }
 
+    /// <summary>
+    /// Determine the endianness
+    /// </summary>
+    [Flags]
+    public enum Endianness
+    {
+        /// <summary>
+        /// This is a fake flag that is used for filter only
+        /// </summary>
+        NULL = 0,
+
+        // TODO: (big|little) "little"
+        Big = 1 << 0,
+        Little = 1 << 1,
+    }
+
     /// <summary>
     /// Determine the emulation status
     /// </summary>