Resolve "Footer System Message covers horizontal scrollbar"

What does this MR do?

This resolves the scrollbar being hidden behind the footer system message. It does force a small space under the boards even when a scrollbar is not present. I believe a better approach may be to have it detect when there is a scroll and perhaps apply this adjustment then, but open to suggestions if someone has a better approach!

Video recording of the local change

Screen_Recording_2020-04-08_at_5.17.33_PM

Closes #30853 (closed)