Also reload python's `site` module which handles `site-packages`.

In case a package has been installed into the current python process 'site-packages', the 'site' module needs to be reloaded in order for the newly installed package to be importable.
The site reload needs to be done on the state module refresh routine.
Merge pull request #6871 from s0undt3ch/features/states-reload

Also reload python's `site` module which handles `site-packages`.