Implement Initialize method in Editor class and override in derived editors

src/app/editor/system/settings_editor.cc

@@ -21,6 +21,8 @@ using ImGui::TableHeadersRow;
 using ImGui::TableNextColumn;
 using ImGui::TableSetupColumn;
 
+void SettingsEditor::Initialize() {}
+
 absl::Status SettingsEditor::Update() {
   if (BeginTabBar("Settings", ImGuiTabBarFlags_None)) {
     if (BeginTabItem("General")) {

src/app/editor/system/settings_editor.h

@@ -208,9 +208,8 @@ static void ShowExampleAppPropertyEditor(bool* p_open) {
 class SettingsEditor : public Editor {
  public:
   SettingsEditor() : Editor() { type_ = EditorType::kSettings; }
-
+  void Initialize() override;
   absl::Status Update() override;
-
   absl::Status Undo() override { return absl::UnimplementedError("Undo"); }
   absl::Status Redo() override { return absl::UnimplementedError("Redo"); }
   absl::Status Cut() override { return absl::UnimplementedError("Cut"); }