Consolidate setter code

SabreTools.DatItems/Formats/File.cs

@@ -326,24 +326,6 @@ namespace SabreTools.DatItems.Formats
 
         #endregion
 
-        #region Manipulation
-
-        /// <inheritdoc/>
-        public override bool SetField(DatItemField datItemField, string value)
-        {
-            // Get the correct internal field name
-            string? fieldName = datItemField switch
-            {
-                // TODO: Figure out what fields go here
-                _ => null,
-            };
-
-            // Set the field and return
-            return FieldManipulator.SetField(_internal, fieldName, value);
-        }
-
-        #endregion
-
         #region Sorting and Merging
 
         /// <inheritdoc/>