feat: no_std

[hussein-aitlahcen]

Hi, making this crate no_std would allow us to embed the crate itself as setup input and hence, having a recursive zkWasm?

[lanbones]

We would like to make it no_std to improve its portability, but we now have some feat in higher priority. I guess recursive zkWasm just depends on a verification key instead of the whole circuits, so the no_std is not that important for a recursive zkWasm.