Checklist

1. If you've added code that should be tested, add tests
2. If you've changed APIs, update (or create!) the documentation
3. Ensure the tests pass
4. Run ./python-format.sh to make sure that your code lints and that you've followed our coding style
5. Write a title and, if necessary, a description of your work suitable for publishing in our release notes
6. Mention any related issues in this repository (as #ISSUE) and in other repositories (as kobotoolbox/other#ISSUE)
7. Open an issue in the docs if there are UI/UX changes
8. Create a testing plan for the reviewer and add it to the Testing section

Description

Fixed Project > Data > Downloads table displaying wrong text in the "Language" column. This was happening when "XML values and headers" or "Labels" was selected in "Value and header format".

Notes

We broke this in #4933. It would be immediately spotted if /jsapp/js/components/projectDownloads was typescriptized.

Testing

Test this without fix first. The steps are:

1. Create a small project
2. Deploy project
3. Add one submission
4. Go to Poject > Data > Downloads
5. Set "Value and header format" to "Labels" and click "Export"
6. Observe export being added (after a short moment), and in the column "Language" you will see "_default" (:bug:)
7. Set "Value and header format" to "XML values and headers" and click "Export"
8. Observe export being added (after a short moment), and in the column "Language" you will see "_xml" (:bug:)

There is a screenshot at #5171

Related issues

Fixes #5171
Followup to #4933