Add a `from_value_ref` function to deserialize structs with `#[serde(borrow)]`

[SamWilsn]

I'm not 100% sure such an idea would work, but here's the problem I'm having:

#[derive(Deserialize)]
struct Foo<'a> {
    #[serde(borrow)]
    inner: &'a str,
}

If I want to deserialize such a struct, and the JSON contains escaped characters, serde_json can't replace the escape sequences with the correct characters.

What if I first deserialized to a serde_json::Value, then deserialized from that to my target struct?