Optimize packaging bundle core logic

优化了打包的核心逻辑，支持设置依赖资源收集器。

Assets/YooAsset/Editor/AssetBundleBuilder/BuildSystem/TaskAttribute.cs

@@ -0,0 +1,14 @@
+using System;
+
+namespace YooAsset.Editor
+{
+	[AttributeUsage(AttributeTargets.Class)]
+	public class TaskAttribute : Attribute
+	{
+		public string Desc;
+		public TaskAttribute(string desc)
+		{
+			Desc = desc;
+		}
+	}
+}