Add search input delay of 200ms

Elwig/Windows/MemberAdminWindow.xaml.cs

@@ -50,6 +50,9 @@ namespace Elwig.Windows {
                 (PhoneNr9TypeInput, PhoneNr9Input, PhoneNr9CommentInput),
             };
             foreach (var input in PhoneNrInputs) input.Item1.ItemsSource = PhoneNrTypes;
+
+            InitializeDelayTimer(SearchInput, SearchInput_TextChanged);
+            SearchInput.TextChanged -= SearchInput_TextChanged;
         }
 
         private void Window_Loaded(object sender, RoutedEventArgs evt) {