优化更新代码，添加界面功能并整合

WPFluent/Controls/AnimatedImage/AnimationProvider.cs

@@ -0,0 +1,24 @@
+using System;
+using System.Threading.Tasks;
+using System.Windows.Media.Animation;
+using System.Windows.Media.Imaging;
+
+namespace WPFluent.Controls;
+
+internal abstract class AnimationProvider : IDisposable
+{
+    protected AnimationProvider(Uri path)
+    {
+        Path = path;
+        Animator = new();
+        Animator.KeyFrames.Add(new DiscreteInt32KeyFrame(0, KeyTime.FromTimeSpan(TimeSpan.Zero)));
+    }
+
+    public Uri Path { get; }
+
+    public Int32AnimationUsingKeyFrames Animator { get; protected set; }
+
+    public abstract void Dispose();
+
+    public abstract Task<BitmapSource> GetRenderedFrame(int index);
+}