Allow switching language in wiki

[MingxuanGame]

• Maybe duplicated of Add a dropdown menu to switch wiki content language #35024
• Unbind between wiki language and game language
• Add fallback notice when no translation
• Add outdated translation notice

[peppy]

This is LLM generated isn't it?

[MingxuanGame]

This is LLM generated isn't it?

UI was assisted. logic is hand-written

[gagahpangeran]

I compare with the previous attempt of this PR on #35024 (which is still open). This PR basically the same as that.

The difference is the implementation of the dropdown UI part. I assume this is the part of the code that is LLM assisted as you said before.

Reading that part of the code is a bit confusing, at least for me. Why is there so many complicated logic for this dropdown? For example, what's the purpose of syncExternalToDropdown() and suppressCurrentPropagation in the dropdown? And also there is no any explanation about that.

[peppy]

Let's just leave the previuos attempt open.