Clean up sfml_title_screen::exec

[richelbilderbeek]

Is your feature request related to a problem? Please describe.

Currently, sfml_title_screen::exec looks like this:

void sfml_title_screen::exec()
{
  //...

    {
      switch (event.type) //!OCLINT TODO too few branches, please fix
      {
        //...
      }
    }

    //m_bg_sprite.setPosition(sf::Vector2f(m_window.getView().getCenter().x -
    //                                     m_bg_sprite.getTexture()->getSize().x,
    //                                     m_window.getView().getCenter().y -
    //                                     m_bg_sprite.getTexture()->getSize().y));

    //...
  }
}

The OCLint tag and the commented code appear to be a left-over from the past.

Describe the solution you'd like

Remove the OCLint tag. Remove the commented code.

All tests should keep passing.

Describe alternatives you've considered

None.

Additional context

None.