* All tests pass under circom-2 feature flag

- Check for version in WASM, default to version 1
- Include Circom1 when Circom 2 feature flag is enabled

Currently a lot of code duplication. Once Circom-2 is more stable and
proven to work in the wild, feature flag can be removed.

* Separate Circom 1 and Circom2 witness calculation

* Cleanup

* WitnessCalculator helpers for Circom 1 and 2

Also make helper fn private

* Move comment

* Fix expression return

* cargo fmt

* Add cargo test circom-2 to ci

* Early exit in error callback from Wasm

This avoids Wasm execution hanging due to problems such as wrong public
input.

Mimics circom_runtime behaviour with less detailed debug information.

See https://github.com/iden3/circom_runtime/blob/master/js/witness_calculator.js#L52-L64

Adds test for wrong public input. Without early exit, the test stalls.
With it, the Circom build step fails as expected.

* chore: clean up error handling

* ci: add caching

Co-authored-by: Georgios Konstantopoulos <me@gakonst.com>

* feat: add function for calculating the coefficients

* fix tests / debug coeffs

* feat: use groth16 with configurable matrices

* test: add no r1cs test

* test: add a test to check matrices values

* scaffold of the matrix calculation

* feat: correctly load and use matrices in the without_r1cs variant

* chore: cargo fmt

* chore: cargo fmt / lints

* ci: do not double run tests

* fix: calculate correctly points at inf

* test: use correct abicoder v2 types

Co-authored-by: Kobi Gurkan <kobigurk@gmail.com>