QmlDesigner: Auxiliary data auto-fold

- Made TextEditorWidget::restoreState() virtual
 - Added function to fold qml Auxiliary Data
 - Extended settings page to fit the new option

Task: QDS-1667
Change-Id: Id1256fcc72a67ac822888d5fd2e23d6076349573
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@qt.io>
Reviewed-by: Thomas Hartmann <thomas.hartmann@qt.io>

src/plugins/qmljseditor/qmljseditor.h

@@ -60,6 +60,7 @@ public:
     QmlJSEditorWidget();
 
     void finalizeInitialization() override;
+    bool restoreState(const QByteArray &state) override;
 
     QmlJSEditorDocument *qmlJsEditorDocument() const;
 
@@ -92,6 +93,7 @@ private:
     void semanticInfoUpdated(const QmlJSTools::SemanticInfo &semanticInfo);
 
     void updateCodeWarnings(QmlJS::Document::Ptr doc);
+    void foldAuxiliaryData();
 
 protected:
     void contextMenuEvent(QContextMenuEvent *e) override;