* replace i32 by u32

* fix overflow in usize

* add testcase for u32 input

* Import circom-2 test vectors

* Add failing test under feature flag

* Add exceptionHandler

* Add showSharedRWMemory

* Add getFieldNumLen32 and disable getFrLen

* Add getVersion

Also print version, n32

* Add getRawPrime

- Disable getPtrRawPrime
- Write as conditional cfg code blocks

* Refactor cfg code blocks

* Add readSharedRWMemory and get prime from WASM mem

- Add fromArray32 convenience function

* WIP: Debug R1CSfile header

field_size in header is 1, not 32 as expected

Don't see anything recently changed here:
https://github.com/iden3/r1csfile/blob/master/src/r1csfile.js (used by snarkjs)

But this seems new: 0149dc0643/constraint_writers/src/r1cs_writer.rs

* Add CircomVersion struct to Wasm

* XXX: Enum test

* Trait version

* Move traits to Circom, CircomBase, Circom2

* Simplify Wasm struct and remove version

* Feature gate Circom1/Circom2 traits

* Use cfg_if for witness calculation

Make normal dependency

* Fix visibilty for both test paths

* Remove println

Can introduce tracing separately

* refactor

* Make clippy happy with imports, unused variables

* 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>