add unit test and finish operator test

BallanceTASEditor/UI/Util.cs

@@ -0,0 +1,24 @@
+using BallanceTASEditor.Core.TASStruct;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace BallanceTASEditor.UI {
+
+
+    public enum ToolMode {
+        Cursor,
+        Fill,
+        Overwrite
+    }
+
+    public struct CellPosition {
+        public CellPosition(int column, FrameDataField field) {
+            this.column = column;
+            this.field = field;
+        }
+        public int column;
+        public FrameDataField field;
+    }
+}