Add PCL_EXPORTS where missing in template instantiations, change order of template instantiations where otherwise the visibility attribute of the parent class would be overwritten by the child class.
This is split off from #5779 which has become a bit large
Add PCL_EXPORTS where missing in template instantiations, change order of template instantiations where otherwise the visibility attribute of the parent class would be overwritten by the child class. This is split off from #5779 which has become a bit large