**Problem:**
An editor using the UI can by default not add a `mul` label or alias in the termbox as that language does not show up.
**Steps to test:**
* Be sure you are not using `mul` as your display language (e.g. uselang=mul)
* Be sure you have no Babel for mul set up.
* Open any Item page e.g. https://test.wikidata.org/wiki/Q172818
What happens:
* You have no way of creating a mul label or alias in the termbox.
What should happen instead:
* `mul` should always show up in the list of languages (as the first language, see T316767).
* Using the termbox you can create a mul label or alias.
**Acceptance criteria:**
[] On Items `mul` shows up in the list of languages in the termbox by default.
[] Please make sure that
[] this changes affects only Items and not Properties.
[] `mul` is the first language in the list (see T316767).