Extract XCUI selection model and layout lab click selection

engine/include/XCEngine/UI/Widgets/UISelectionModel.h

@@ -0,0 +1,26 @@
+#pragma once
+
+#include <string>
+#include <string_view>
+
+namespace XCEngine {
+namespace UI {
+namespace Widgets {
+
+class UISelectionModel {
+public:
+    bool HasSelection() const;
+    const std::string& GetSelectedId() const;
+    bool IsSelected(std::string_view id) const;
+
+    bool SetSelection(std::string selectionId);
+    bool ClearSelection();
+    bool ToggleSelection(std::string selectionId);
+
+private:
+    std::string m_selectedId = {};
+};
+
+} // namespace Widgets
+} // namespace UI
+} // namespace XCEngine