**Problem:**
When displaying an Item or Property page, the page heading usually applies language fallback to the label and description. The problem is that doing anything with the termbox which causes the heading to update causes the language fallback to no longer be applied
**Examples:**
e.g.
* On https://test.wikidata.org/wiki/Q38378?uselang=de-ch `de-ch` falls back to `de` for the label and `en` for the description
* On https://test.wikidata.org/wiki/Q38379?uselang=de-ch `de-ch` falls back to `en` for the label and `de` for the description
**Steps to reproduce:**
A
* Make any change in the termbox and save it.
* After saving the heading is refreshed and no longer applies language fallback
B
* Make any change to the language current set as the interface language and then cancel editing.
* The heading updates when making the changes, the changes are reverted after cancelling, but language fallback is no longer applied
**Notes:**
* This is a side-effect of T98014. PHP does language fallback in the header section, but JS does not. So, if you edit the terms of an entity which doesn't have terms in the UI language, after leaving edit mode the header section might look different than it does after a reload.
* This will get more visible after releasing language code `mul` (T285156).
**Acceptance criteria:**
[] The language fallback of the page title is respected (in both cases A and B), so that the page title is always up-to date with the rest of the Item.