Lots of code refactoring to use XAML behaviors instead of code-behind

New Save button in the AppBar
EntryPage now uses the same AppBar as GroupPage (but not shared...)
Some new Symbol mappings

ModernKeePass/Pages/OpenDatabasePage.xaml.cs

@@ -45,10 +45,5 @@ namespace ModernKeePass.Pages
             if (file == null) return;
             Model.OpenFile(file);
         }
-
-        private void PasswordUserControl_PasswordChecked(object sender, PasswordEventArgs e)
-        {
-            _mainFrame.Navigate(typeof(GroupDetailPage), e.RootGroup);
-        }
     }
 }