Save error is now handled via Messenger instead of unhandled exception handler (which didn't work)

Save as actually works now
WIP Styles
Code cleanup

ModernKeePass/Views/MainPageFrames/RecentDatabasesPage.xaml.cs

@@ -1,7 +1,5 @@
 // Pour en savoir plus sur le modèle d'élément Page vierge, consultez la page http://go.microsoft.com/fwlink/?LinkId=234238
 
-using ModernKeePass.ViewModels;
-
 namespace ModernKeePass.Views
 {
     /// <summary>