Universal Language Selector limits the list of languages to 10 and adds a button underneath that launches Universal Language Selector. This will cause problems for us as we move the language button position, so we will need a mechanism for disabling the loading of this module for modern Vector.
{F32376253}
We will wire up a modified version of this code for Vector which simply renders the button.
# Acceptance criteria
[] The code for the click handler for the language button is factored out into a lightweight module.
[] The UniversalLanguageSelector hook will need to check the Vector skin version and not load `ext.uls.compactlinks` if modern Vector is enabled.
[] When modern Vector is enabled a new module will be loaded that enhances the button being created in T260738 with the new factored out click handler
[] The new module should be tiny (<1kb)
# QA steps
Enable "Use a compact language list, with languages relevant to you." on https://en.wikipedia.beta.wmflabs.org/wiki/Special:Preferences#mw-prefsection-rendering and visit the main page. Check the button there works.