Make strings for the current language and language switching available on Rust side

[Raphiiko]

Currently, the Rust side cannot access any translations. These are only available in the frontend.

Ideally, the frontend should send the translations to the Rust side on startup, as well as whenever the language is changed.

The Rust side should be able to update its shown translations (e.g. for the system tray from #22) whenever the active language is updated.

[SticksDev]

Maybe this is best suited for a tauri command?

see https://tauri.app/v1/guides/features/command

could just have a command that tells rust what lang to use and go from there

[Raphiiko]

Oh yeah it very much is. How to get things from/to the Rust side isn't really an issue.
OyasumiVR already makes heavy use of Tauri commands (and events). Barely anything it does would be possible without any native functionality written in Rust.

The complexity comes more from how to structure this in a sane and generic way: You ideally only want to have a single source of translations, have the ability to update everything on the fly while keeping things in sync, and have it be a solution that is generic enough that it can be reused for various (future) translations, e.g. not just the system tray.

It's likely not rocket science, but it's mostly a nice to have, and for me personally, the gain of looking into it currently isn't worth the time that I could spend on improving OyasumiVR elsewhere.