EffectMaker: Scroll to bottom when adding an effect node

Fixes: QDS-11434
Change-Id: Ia1010f83468e3243eff4f3f0fbecb4ef733b523b
Reviewed-by: Miikka Heikkinen <miikka.heikkinen@qt.io>

share/qtcreator/qmldesigner/effectMakerQmlSources/EffectMaker.qml

@@ -149,6 +149,13 @@ Item {
             clip: true
             interactive: !HelperWidgets.Controller.contextMenuOpened
 
+            onContentHeightChanged: {
+                if (scrollView.contentItem.height > scrollView.height) {
+                    let lastItemH = repeater.itemAt(repeater.count - 1).height
+                    scrollView.contentY = scrollView.contentItem.height - lastItemH
+                }
+            }
+
             Column {
                 width: scrollView.width
                 spacing: 1