Custom apps load STLs as Segmentation by default

[sjh26]

I have observed this is multiple custom app. When loading STLs in the Add Data dialog, the default option is as a segmentation.

Example affected app (AevaSlicer): https://data.kitware.com/#collection/5e387f9caf2e2eed3562242e/folder/5e3888e3af2e2eed35628e50