Refactor SelectedTab to DeclarativeProperty

src/AppCommon/FileTime.App.Core.Abstraction/ViewModels/IAppState.cs

@@ -8,16 +8,15 @@ namespace FileTime.App.Core.ViewModels;
 public interface IAppState
 {
     ReadOnlyObservableCollection<ITabViewModel> Tabs { get; }
-    IObservable<ITabViewModel?> SelectedTab { get; }
+    IDeclarativeProperty<ITabViewModel?> SelectedTab { get; }
     IObservable<string?> SearchText { get; }
     IDeclarativeProperty<ViewMode> ViewMode { get; }
     DeclarativeProperty<string?> RapidTravelText { get; }
-    ITabViewModel? CurrentSelectedTab { get; }
     ITimelineViewModel TimelineViewModel { get; }
 
     void AddTab(ITabViewModel tabViewModel);
     void RemoveTab(ITabViewModel tabViewModel);
     void SetSearchText(string? searchText);
     Task SwitchViewModeAsync(ViewMode newViewMode);
-    void SetSelectedTab(ITabViewModel tabToSelect);
+    Task SetSelectedTabAsync(ITabViewModel tabToSelect);
 }