Gui: Refactor LCS fixes

* use early exit to highlight main execution path
* use `auto*` for pointer
* use getObject<T>() instead of casting result from getObject()
* remove empty updateData()
* rename origin to lcs in setTemporaryVisibility for clarity

src/Gui/ViewProviderCoordinateSystem.h

@@ -100,7 +100,6 @@ public:
     static const uint32_t defaultColor = 0x3296faff;
 
 protected:
-    void updateData(const App::Property*) override;
     bool onDelete(const std::vector<std::string> &) override;
 
 private: