Wrong `From` implementation.

[gabrik]

Hi all,

I just noticed a crash on my application when calling if let Ok(mime: Mime) = x.try_into() beacuse of the unwrap() in: https://github.com/http-rs/http-types/blob/v2.12.0/src/mime/mod.rs#L131

I think TryFrom implementation would be nice to have as would avoid this kind of errors.

I know I can use the FromStr (that what I'm doing after I discovered the issue), but the I still think it is worth to have the TryFrom

I can come with a PR.

[gabrik]

Acutally, let me update this by changing the name. Current From implementation is wrong as it contains and unwrap that can fail.

So either it becomes a TryFrom or it can be removed as the FromStr is already there.