fix: remove unused imports in Dart files

Author: kkweon

client/lib/widgets/main/main_screen_favorite_view.dart

@@ -1,7 +1,6 @@
 import 'package:flutter/material.dart';
 import 'package:pr12er/view_models/view_model_videos.dart';
 import 'package:pr12er/widgets/main/pr12video.dart';
-import 'package:pr12er/widgets/main/video_search_delegate.dart';
 import 'package:provider/provider.dart';
 
 import '../../protos/pkg/pr12er/messages.pb.dart';

client/lib/widgets/main/main_screen_list_view.dart

@@ -1,6 +1,5 @@
 import 'package:flutter/material.dart';
 import 'package:pr12er/widgets/main/pr12video.dart';
-import 'package:pr12er/widgets/main/video_search_delegate.dart';
 import "../../protos/pkg/pr12er/messages.pb.dart";
 
 class MainScreenListView extends StatelessWidget {

client/lib/widgets/main/video_search_delegate.dart

@@ -85,13 +85,12 @@ class VideoSearchDelegate extends SearchDelegate {
   }
 
   List<Video> getInterestedVideos() {
-    var videos = dataRef.where((video) {
+    return dataRef.where((video) {
       final searchLower = query.toLowerCase();
       final titleLower = video.title.toLowerCase();
 
       return titleLower.contains(searchLower);
     }).toList();
-    return videos;
   }
 
   @override