UniversalLanguageSelector will enhance an existing button with the mw-interlanguage-selector class.
- The class mw-interlanguage-selector class is added to the button.
- When ULS enhances the button, the hover effect should be disabled.
We may need to check the existence/state of the ULS module and use client-js to determine whether to disable the ULS hover effect.
- Visit https://en.wikipedia.beta.wmflabs.org/wiki/Test_indicators and confirm you can switch to all 7 available languages
- Check Firefox, Chrome, Safari, Edge (this can be deferred if a general QA of the feature later is being planned).