Add action triggering display of master effects

src/kdenliveui.rc

 <!DOCTYPE kpartgui SYSTEM "kpartgui.dtd">
-<kpartgui name="kdenlive" version="167" translationDomain="kdenlive">
+<kpartgui name="kdenlive" version="168" translationDomain="kdenlive">
   <MenuBar>
     <Menu name="file" >
       <Action name="dvd_wizard" />
@@ -128,6 +128,7 @@
       <Action name="save_selection" />
       <Action name="send_library" />
       <Menu name="timeline_tracks" ><text>Tracks</text>
+        <Action name="master_effects" />
         <Action name="insert_track" />
         <Action name="delete_track" />
 	<Separator />

src/mainwindow.cpp

@@ -1428,6 +1428,13 @@ void MainWindow::setupActions()
     QAction *insertTrack = new QAction(QIcon(), i18n("Insert Track"), this);
     connect(insertTrack, &QAction::triggered, this, &MainWindow::slotInsertTrack);
     timelineActions->addAction(QStringLiteral("insert_track"), insertTrack);
+    
+    QAction *masterEffectStack = new QAction(QIcon::fromTheme(QStringLiteral("kdenlive-composite")), i18n("Master effects"), this);
+    connect(masterEffectStack, &QAction::triggered, [&]() {
+        pCore->monitorManager()->activateMonitor(Kdenlive::ProjectMonitor);
+        getCurrentTimeline()->controller()->showMasterEffects();
+    });
+    timelineActions->addAction(QStringLiteral("master_effects"), masterEffectStack);
 
     QAction *deleteTrack = new QAction(QIcon(), i18n("Delete Track"), this);
     connect(deleteTrack, &QAction::triggered, this, &MainWindow::slotDeleteTrack);