Export with fallback language is missing terms

[simonschllng]

Describe the bug
If you select a fallback language, the resulting export will miss some terms.

To Reproduce
Steps to reproduce the behavior:

1. Add three languages
2. Add three direct terms and three nested ones "group.term"
3. Add all translations in the "main" language (example below: en_GB)
4. Add some but not all translations per other language.
5. Export all languages without fallback.
6. Export the two additional with the "main" one as fallback.

Expected behavior

• The export without fallback contains all terms, some of them without translations as empty string ""
• The export with fallback contains all terms, missing ones replaced by the translation from the main language, no empty strings.

Screenshots

Languages:

Terms, same w/o nesting:

Second language:

Compare with and w/o fallback:

Compare all w/o fallback:

Compare all with fallback:

** Environment (please complete the following information):**

• Device: Desktop
• OS: Linux
• Browser chrome
• Version [e.g. 22]

Additional context
Add any other context about the problem here.