📝 Review language tags and add mul

[RVA2869]

Description

I added mul to all queries except topics.rq.
I also fixed some errors. For example German in East Timor and added some more official languages.

Side note

I'm not sure what to do with this:

SERVICE wikibase:label {
    # this might need to be updated when new countries are added
    bd:serviceParam wikibase:language "en,sv,de,mul" .

Are all languages supposed to be included or?

Fixes #469

PR Details

Type of Change

• Bug fix
• New feature
• Breaking change
• Documentation update
• Code refactor

Checklist

Please ensure the following before submitting the PR:

• I have tested the changes locally, and they work as expected.
• The code follows the project's coding standards and conventions.
• Any query changes have been verified and are working correctly.
• I have updated relevant documentation (if needed).
• I have added unit tests or performed manual testing where necessary.

Screenshots (applicable to user interface changes)

[Ainali]

Oh, German in East Timor was not an accident, it was there on purpose as it happens that it is a German on German Wikipedia that does most of the edits.

[RVA2869]

Oh, German in East Timor was not an accident, it was there on purpose as it happens that it is a German on German Wikipedia that does most of the edits.

I see,... but that's a bit strange, isn't it? If the 3 previous languages fail (worst case senario), then German is visible in a non-German speaking country.

[Ainali]

I see,... but that's a bit strange, isn't it? If the 3 previous languages fail (worst case senario), then German is visible in a non-German speaking country.

Well, it is a bit obscure, but more human-readable than a Qid which would otherwise be the case.