* refactor r1cs::is_valid and provider::cpu_best_multiexp (microsoft#240)

* refactor: r1cs is valid

* refactor: msm parallel iteration

* chore: fix clippy

* Expose verifier key's digest with a trait (microsoft#243)

* Expose verifier key's digest with a trait

* run cargo fmt and clippy

* use rayon to compute in parallel (microsoft#245)

* Eliminate unnecessary wraps & use alloc_infallible (microsoft#246)

* feat: Refactor unnecessary wraps in error handling

Revised operations unnecessarily wrapping their return in a Result.

* refactor: Refactor to use infallible allocation across application

- Switched the allocation method to the infallible version, `AllocatedNum::alloc_infallible`, in multiple units (`poseidon.rs`, `bellpepper/mod.rs`, `utils.rs`, `circuit.rs`, `lib.rs`, `nifs.rs`).
  This removed the need for multiple error checks and reduced usage of `Result` return types.

* release 0.27.0 (microsoft#247)

* Reduce hashing costs with a power polynomial in ppsnark (microsoft#248)

* use eq polynomial emulated via power polynomial, to reduce hashing costs

* update version

* add missing file

* Optimize ppsnark (microsoft#250)

* update ppsnark to be more efficient

* remove

* clippy

* use padded

* rayon

* additional rayon

* update version

---------

Co-authored-by: ashWhiteHat <phantomofrotten@gmail.com>
Co-authored-by: Jiaxing Zhao <mrls1219@mail.ustc.edu.cn>
Co-authored-by: Srinath Setty <srinath@microsoft.com>