feat: Deserialize binary as JSON array

[ThetaSinner]

I'm using rmp_serde with serde_json. I want to be able to do something like:

let binary = vec![196, 39, 132, 41, 36, 231, 196, 82, 19, 131, 98, 76, 183, 39, 96, 20, 116, 59, 218, 195, 4, 22, 240, 167, 37, 50, 187, 162, 63, 216, 103, 212, 34, 103, 224, 154, 209, 255, 101, 36, 57];
let t: serde_json::Value = rmp_serde::from_slice(&binary).unwrap();
assert!(matches!(t, serde_json::Value::Array(_)));

It's not a perfect round trip if you try to reverse it because in the other direction this would now serialize as a msgpack array rather than binary data. At least in this direction, I believe it's reasonable to represent binary data as a numeric array.

[ThetaSinner]

I had a go at writing a test for this. Without a Deserializer that will request deserializing binary, I don't think this code can be reached. serde_json won't do that so I'd need some other Deserializer. I'm up for adding one in a test if that's a useful thing to do?