refactor(new_editor): snapshot hosted editor restructuring

new_editor/include/XCEditor/Shell/UIEditorShellCompose.h

@@ -4,17 +4,15 @@
 #include <XCEditor/Menu/UIEditorMenuBar.h>
 #include <XCEditor/Shell/UIEditorStatusBar.h>
 
-namespace XCEngine::UI::Editor {
+namespace XCEngine::UI::Editor::App {
+class BuiltInIcons;
+}
 
-enum class UIEditorShellToolbarGlyph : std::uint8_t {
-    Play = 0,
-    Pause,
-    Step
-};
+namespace XCEngine::UI::Editor {
 
 struct UIEditorShellToolbarButton {
     std::string buttonId = {};
-    UIEditorShellToolbarGlyph glyph = UIEditorShellToolbarGlyph::Play;
+    std::uint8_t iconKind = 0;
     bool enabled = true;
 };
 
@@ -150,7 +148,8 @@ void AppendUIEditorShellCompose(
     const UIEditorShellComposeModel& model,
     const UIEditorShellComposeState& state,
     const UIEditorShellComposePalette& palette = {},
-    const UIEditorShellComposeMetrics& metrics = {});
+    const UIEditorShellComposeMetrics& metrics = {},
+    const App::BuiltInIcons* builtInIcons = nullptr);
 
 void AppendUIEditorShellComposeOverlay(
     ::XCEngine::UI::UIDrawList& drawList,