Add Grumpkin cycle implementation (#181)

* bn256+grumpkin from halo2curves

* chore: Integrate halo2curves more extensively

- Extend existing tests with additional test cases using the new curve types

* fix: Assign correct orders to bn256 and grumpkin scalar fields

- Swap scalar orders between grumpkin and bn256 in `impl_traits!` implementation

* test: Finish improving test integration with halo2curves

- Enhances test coverage for `pasta_curves` and `halo2curves`
- Cleans up commented code in `test_ivc_nontrivial` and `test_ivc_nontrivial_with_compression` tests
- Updates relevant test cases in `src/lib.rs` to include new curve tests

* chore: Remove commented-out/uneeded code in bn254_grumpkin.rs

* test: reproduce test_from_label for bn254_grumpkin

- Implement the `from_label_serial` function in bn254_grumpkin provider
- Add a test to compare parallel and serial implementations of `from_label` function

* refactor: Clean up to_coordinate & summarize changes

* refactor: rename bn254_grumpkin -> bn256_grumpkin

* test: Expand testing for public params digest using bn256 and grumpkin

* chore: Update halo2curves dependency in Cargo.toml

- Updated the `halo2curves` dependency in `Cargo.toml` to the latest version `0.1.0` from a specific git branch.

* refactor: Refactor multi-exponentiation methods across providers

- Updated bn256_grumpkin.rs to use the cpu_best_multiexp function from pasta provider instead of its native function.
- Modified visibility of cpu_best_multiexp function in pasta.rs from private to crate level.

* chore: set up dependencies to import the correct getrandom feature on Wasm

---------

Co-authored-by: Leo Alt <leo@ethereum.org>

src/bellperson/mod.rs

@@ -62,7 +62,7 @@ mod tests {
 
   #[test]
   fn test_alloc_bit() {
-    type G = pasta_curves::pallas::Point;
-    test_alloc_bit_with::<G>();
+    test_alloc_bit_with::<pasta_curves::pallas::Point>();
+    test_alloc_bit_with::<crate::provider::bn256_grumpkin::bn256::Point>();
   }
 }