Add justjson as an alternative json solution.

[kvinwang]

Looks like It won't produce unnecessary fp instructions: https://github.com/khonsulabs/justjson/

And maybe another way: making our own simple JSON parser based on https://github.com/zesterer/chumsky/blob/master/examples/json.rs.

[h4x3rotab]

Looks nice. Do you think it's better than having our own serde json in our own crates (e.g. pink-web3)?

[kvinwang]

Do you think it's better than having our own serde json in our own crates (e.g. pink-web3)?

No, justjson doesn't support serde. It's not easy to replace serde_json with it in pink-web3.

It can be a lightweight alternative to some simple scenarios.