feat(zkvm): state transition function proving using zkvm's

[Sahilgill24]

Description / Motivation

#156

What Changed

The approach is based on this doc ethlambda's stf proving using zkvm's.

Current Progress

• added the StfInput type, which shall be used by the guest-program
• scaffolded the sp1 guest program inside a new guest-program crate
• prover core and prover backend for sp1 with a mock prover is complete

Verification Checklist

• Ran make fmt — clean
• Ran make lint (clippy with -D warnings) — clean
• Ran cargo test --workspace --release — all passing

[Sahilgill24]

Note

I will be updating and adding proper comments where ever necessary and also try to write a more idiomatic approach for the StfInput if possible, the current version is a basic scaffold as mentioned in the 1st step of the implementation plan in the doc.
Also will add more steps to the PR heading as well once sp1 integration is complete, currently on kept the progress status