if only the scope column is visible in the navigation pane, there is no horizontal scroll bar

[jmellorcrummey]

Describe the bug
On Linux, if you shrink the width of the window so that none of the metric columns are visible, the scroll bar disappears.

To Reproduce
Take any database with the 2022.03 viewer and shrink the width

Expected behavior
I think at least one metric should always be at least partially visible when the width of the hpcviewer window is shrunk.

Screenshots

Platform (please complete the following information):
Linux
x86
iris.cs