feat: video download

Signed-off-by: bggRGjQaUbCoE <githubaccount56556@proton.me>

lib/plugin/pl_player/widgets/bottom_control.dart

@@ -45,7 +45,7 @@ class BottomControl extends StatelessWidget {
     }
 
     void onDragUpdate(ThumbDragDetails duration, int max) {
-      if (controller.showSeekPreview) {
+      if (!controller.isFileSource && controller.showSeekPreview) {
         controller.updatePreviewIndex(
           duration.timeStamp.inSeconds,
         );