Remove [Button triggers] from frontend strings

[JacquelineMorrissette]

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. Make sure that your code lints and that you've followed our coding style
5. Write a description of your work suitable for publishing on our forum
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

Description

Move the "[button triggers]" outside of the string to be translated to avoid confusion as to whether or not it should be translated by volunteers

[JacquelineMorrissette]

Assigning to @magicznyleszek for delegation or review