avalonia: Fixed module title renaming, which was broken due to a merge conflict earlier

PRS.Avalonia/PRS.Avalonia/MainViewModel.cs

@@ -1,4 +1,5 @@
 using System.Linq;
+using Avalonia.Threading;
 using CommunityToolkit.Mvvm.ComponentModel;
 using InABox.Avalonia;
 using InABox.Avalonia.Router;
@@ -30,9 +31,15 @@ public partial class MainViewModel : ViewModelBase
                 Content.Deactivate();
             IsTransitioning = true;
             Content = viewModel;
-            Title = viewModel is IModuleViewModel module
-                ? module.Title
-                : Repositories.MaybeMe?.Name ?? "PRS Avalonia";
+            if(viewModel is IModuleViewModel module)
+            {
+                Title = module.GetTitle();
+                module.OnTitleChanged += title => Dispatcher.UIThread.InvokeAsync(() => Title = title);
+            }
+            else
+            {
+                Title = Repositories.MaybeMe?.Name ?? "PRS Avalonia";
+            }
             PrimaryMenu = viewModel.PrimaryMenu;
             SecondaryMenu = viewModel.SecondaryMenu;
             BackButtonVisible = viewModel.BackButtonVisible;