Implemented save as dialog for Windows.

I18N Commander/UI MAUI/Pages/LoadProject.razor.cs

@@ -37,16 +37,14 @@ public partial class LoadProject
 
     }
 
-    private async Task ChooseProjectDestination()
+    private Task ChooseProjectDestination()
     {
-        var projectDestination = await FilePicker.PickAsync(new PickOptions
-        {
-            PickerTitle = "Choose the project destination",
-        });
-
-        if(projectDestination is null)
-            return;
-
-        this.newProjectDestination = projectDestination!.FullPath;
+#if WINDOWS
+        return this.ChooseProjectDestinationWindows();
+#elif MACCATALYST
+        return this.ChooseProjectDestinationMacOS();
+#else
+        return Task.CompletedTask;
+#endif
     }
 }