feat(new_editor): add standalone add-component utility window

new_editor/app/State/EditorUtilityWindowRequestState.cpp

@@ -0,0 +1,26 @@
+#include "State/EditorUtilityWindowRequestState.h"
+
+namespace XCEngine::UI::Editor::App {
+
+void ResetEditorUtilityWindowRequestState(EditorUtilityWindowRequestState& state) {
+    state = {};
+}
+
+void RequestEditorUtilityWindow(
+    EditorUtilityWindowRequestState& state,
+    EditorUtilityWindowKind kind) {
+    if (kind == EditorUtilityWindowKind::None) {
+        return;
+    }
+
+    state.pendingKind = kind;
+}
+
+std::optional<EditorUtilityWindowKind> ConsumeEditorUtilityWindowRequest(
+    EditorUtilityWindowRequestState& state) {
+    const std::optional<EditorUtilityWindowKind> requestedKind = state.pendingKind;
+    state.pendingKind.reset();
+    return requestedKind;
+}
+
+} // namespace XCEngine::UI::Editor::App