QmlDesigner: Sync compilation with add/remove composition nodes

Now when there are no effects, default state is restored
Also some cleanups

Task-number: QDS-11064
Change-Id: Iad25adf2c0f855cb709c494d9f3eb47ef6207d36
Reviewed-by: Mahmoud Badri <mahmoud.badri@qt.io>
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>

src/plugins/effectmakernew/effectmakermodel.cpp

@@ -104,6 +104,9 @@ void EffectMakerModel::setIsEmpty(bool val)
     if (m_isEmpty != val) {
         m_isEmpty = val;
         emit isEmptyChanged();
+
+        if (m_isEmpty)
+            bakeShaders();
     }
 }