重构LineChart和BarChart，移除Line和Bar组件，参数统一放到Serie中配置。

Scripts/UI/Utility/ListPool.cs

@@ -0,0 +1,20 @@
+using System.Collections.Generic;
+
+namespace XCharts
+{
+    internal static class ListPool<T>
+    {
+        private static readonly ObjectPool<List<T>> s_ListPool = new ObjectPool<List<T>>(null, Clear);
+        static void Clear(List<T> l) { l.Clear(); }
+
+        public static List<T> Get()
+        {
+            return s_ListPool.Get();
+        }
+
+        public static void Release(List<T> toRelease)
+        {
+            s_ListPool.Release(toRelease);
+        }
+    }
+}