…rations#122)

* change: Move from `maybe_rayon` to `rayon-1.8`

After seeing the issues with WASM that the last release (`0.5.0`) of
this crate made, the idea is to now control the compatibility with WASM
while at the same time, making it easy to handle.

In this line of work, the idea was to simply do the following:
- Use `rayon 1.8` as a dependency for paralellism which fixes the WASM
  compat issues with `multicore`-related things. See: rayon-rs/rayon#1019
  thanks @han0110 for the suggestion.
- Use conditional dev-dependency loading for `getrandom` such that we
  can compile the lib for WASM-targets in the CI without needing to have
  the dependency being pulled downstream.
- The `multicore` module is gone, and the rest of the code has been
  refactored since the "fallback" is now handled by rayon itself.

* change: Update CI to account for WASM compat

* chore: Add paralellism section to README

* chore: Fix CI missing "

* chore:  Split WASM build & add targets

* chore: Test all features for regular-target  builds

* chore: Address review nits

* impl CIOS

* more details

* add Fast CIOS for bn256

* rolled Fast CIOS

* clean comment

* geq for last line in bigint_geq

* update comment to include WORD_SIZE

* mod in montomgery

* cargo fmt

* cargo clippy

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Co-authored-by: sragss <[email protected]>

* impl msm with batch addition

* bring back multiexp serial

* parallelize coeffs to repr

Co-authored-by: Han <[email protected]>

* parallelize bases to affine

Co-authored-by: Han <[email protected]>

* add missing dependency

* bring back old implementation

postfix new one as `_independent_points`

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Co-authored-by: Han <[email protected]>