CmdPal: Filtering out pinned apps on search (#40785)

Closes #40781 

Filters out TopLevelCommands whose Id matches an app coming from the
`AllAppsCommandProvider.Page.GetItems()`.

Hate adding processing there, but without adding some type of `bool
HideMeOnSearch` to something low enough (like ICommandItem), I don't see
another way to distinguish these.

src/modules/cmdpal/Microsoft.CmdPal.UI.ViewModels/Commands/MainListPage.cs

@@ -164,6 +164,11 @@ public partial class MainListPage : DynamicListPage,
                 if (_includeApps)
                 {
                     IEnumerable<IListItem> apps = AllAppsCommandProvider.Page.GetItems();
+                    var appIds = apps.Select(app => app.Command.Id).ToArray();
+
+                    // Remove any top level pinned apps and use the apps from AllAppsCommandProvider.Page.GetItems()
+                    // since they contain details.
+                    _filteredItems = _filteredItems.Where(item => item.Command is not AppCommand);
                     _filteredItems = _filteredItems.Concat(apps);
                 }
             }