Created frame for FindWindow, shortened CoinCollection

PcgsInvUi/ViewModels/FindWindowViewModel.cs

@@ -0,0 +1,9 @@
+using System.Reactive;
+using ReactiveUI;
+
+namespace PcgsInvUi.ViewModels;
+
+public class FindWindowViewModel : ViewModelBase
+{
+    public ReactiveCommand<Unit, object> OkCommand { get; } = ReactiveCommand.Create(() => (object)1);
+}