Make the poseidon to be a separated package

[chiro-hiro]

Poseidon circuit had been implemented here but we want to create a crate out of it. So please make it to be an independent crate.

https://github.com/orochi-network/orochimaru/tree/main/zkmemory/src/poseidon

[NOOMA-42]

I'd like take this issue and also clarify a few question:

1. What I understand is I need to make poseidon a separate package and I'd most possibly do it this way. Does this align with what you expect?

├── src/
│   ├── commitment/
│   ├── constraints/
│   ├── poseidon/
│   │   ├── mod.rs
│   │   ├── poseidon_constants.rs
│   │   └── poseidon_hash.rs
│   ├── base.rs
│   ├── config.rs
│   ├── error.rs
│   ├── lib.rs
│   └── machine.rs
├── poseidon_hash/  <-- Make a new directory 
│   ├── src/
│   │   └── lib.rs
│   │   ├── poseidon_constants.rs
│   │   └── poseidon_hash.rs
│   └── Cargo.toml
├── Cargo.toml

2. There are some with visibility only to crate level
   pub (crate) const ROUND_CONSTANTS_FR
   If I make it a separate package, Is it okay to make these const variables public to external? namely,
   pub const ROUND_CONSTANTS_FR

[chiro-hiro]

Please move on with this 👍

[NOOMA-42]

closed by #77