* chore(messages): npm run messages
This is the raw changes made by `npm run messages`, without any
manual reverts / backporting.
* fix(messages): Backport TranslateWiki hints (with edits)
Backport changes made to qqq.json by TranslateWiki editors to
messages.json, with some modifications.
See https://translatewiki.net/wiki/Template:Optional for details
of how the {{Optional}} template works.
* chore(messages): Apply backported messages.js changes to qqq.json
Also manually revert deletion of translation credits.
