info: fixed metadata search bar style

lib/widgets/search/search_delegate.dart

@@ -42,10 +42,6 @@ class CollectionSearchDelegate {
 
   CollectionSearchDelegate({@required this.source, this.parentCollection});
 
-  ThemeData appBarTheme(BuildContext context) {
-    return Theme.of(context);
-  }
-
   Widget buildLeading(BuildContext context) {
     return Navigator.canPop(context)
         ? IconButton(

lib/widgets/search/search_page.dart

@@ -88,7 +88,7 @@ class _SearchPageState extends State<SearchPage> {
 
   @override
   Widget build(BuildContext context) {
-    final theme = widget.delegate.appBarTheme(context);
+    final theme = Theme.of(context);
     Widget body;
     switch (widget.delegate.currentBody) {
       case SearchBody.suggestions:

lib/widgets/viewer/info/info_search.dart

@@ -24,11 +24,6 @@ class InfoSearchDelegate extends SearchDelegate {
           searchFieldLabel: searchFieldLabel,
         );
 
-  @override
-  ThemeData appBarTheme(BuildContext context) {
-    return Theme.of(context);
-  }
-
   @override
   Widget buildLeading(BuildContext context) {
     return IconButton(