增加桑基图相关支持

Editor/Series/SerieDataLinkDrawer.cs

@@ -0,0 +1,24 @@
+using UnityEditor;
+using UnityEngine;
+using XCharts.Runtime;
+
+namespace XCharts.Editor
+{
+    [CustomPropertyDrawer(typeof(SerieDataLink), true)]
+    public class SerieDataLinkDrawer : BasePropertyDrawer
+    {
+        public override string ClassName { get { return "Link"; } }
+        public override void OnGUI(Rect pos, SerializedProperty prop, GUIContent label)
+        {
+            base.OnGUI(pos, prop, label);
+            if (MakeComponentFoldout(prop, "", true))
+            {
+                ++EditorGUI.indentLevel;
+                PropertyField(prop, "m_Source");
+                PropertyField(prop, "m_Target");
+                PropertyField(prop, "m_Value");
+                --EditorGUI.indentLevel;
+            }
+        }
+    }
+}