fixes #4985 - nutupane - add padding-right to the nutupane-bar

This commit is to add some padding to the right of the nutupane-bar.
This will fix an issue where buttons are being cut-off.

This PR is to address the issue in the near-term; however, it is possible
that as the patternfly changes are introduced, this is no longer necessary.
(Reference: https://github.com/Katello/katello/pull/3898)