refactor: Move sketch mode camera animations to Camera class

Co-authored-by: aider (gemini/gemini-2.5-pro) <aider@aider.chat>

src/ViewportWidget.h

@@ -73,6 +73,9 @@ signals:
     void planeSelected(SketchPlane plane);
     void toolDeactivated();
 
+private slots:
+    void onRestoreStateAnimationFinished();
+
 protected:
     void initializeGL() override;
     void paintGL() override;