When a `KDirOperator` view is used in {nav Detailed} or {nav Detailed Tree} view, when there isn't enough horizontal space, the {nav Name} column currently gets squeezed and becomes illegible.
This patch fixes that by making the name column fixed-width so it never gets too small to read the contents; instead the view sprouts a horizontal scrollbar, which is preferable.
BUG: 401506
FIXED-IN: 5.54