Language negotiation strategy

[sheosi]

In some cases the skills don't have the same locale that the server requested, in that case we need to negotiate. Remember, a locale consists of a language and a country, plus some other details.

Here are the strategies available in fluent-langneg (a Rust crate for language negotiation) (https://docs.rs/fluent-langneg/latest/fluent_langneg/negotiate/index.html):

• Exact match
• Locale range
• Use ICU LikelySubtags
• Different variant of the same locale
• Only consider language stripped and then maximize it
• Different region same locale

[sheosi]

Personally I like the different region, same locale. But we would still need some fallback if languages are not compatible.