When exporting translation package, Name in URL field ignored

Description

Steps to reproduce:

1. Create a page called Page 1.
2. Create a Swedish version of Page 1 called Page 1 - SV.
3. Add Page 1 - SV to a translation project called Translation.
4. Switch to Translation project view.
5. Select Options > Download Translation Package to download the translation package.

Expected:
The Name in URL field is in the translation file.

Actual:
The Name in URL field is not added to the translation file.