Give aggregate info in overlay in ListView

## Prerequisites
- [* ] I have searched open and closed issues for duplicates.

## Feature
In ListView the information overlay is suppressed. This makes sense for single files as the same information is available in the view. However, it would be useful, and more consistent to show aggregate information when multiple files are selected, as happens in the other views.

**Describe the solution you'd like**
Do not suppress the information overlay when more than one file is selected when in ListView.

**Existing work**
All the required code exists in Files - it should just require tweaking the suppression logic.