[instrument_builder] Untranslated fields

[CamilleBeau]

Describe the bug

To Reproduce
Steps to reproduce the behavior (attach screenshots if applicable):

1. Go to the instrument builder in french
2. See that "Browse" is not translated when uploading a linst file (this is true in japanese as well)
3. After adding fields, see that "Delete" is not translated (this is only true for french)