Replace panics with Results in the Rust bindings for much more descriptive failures

[bkase]

via @mrmr1993 There's a 2 line change to the WASM bindings which will give you a descriptive error instead of panicking when proving fails.

Make https://github.com/MinaProtocol/mina/blob/a3661e44e01b2c400d6eb5ac254c6ab7a91b3623/src/lib/crypto/kimchi_bindings/wasm/src/plonk_proof.rs#L551 return a Result<WasmProverProof, JSValue>
Change https://github.com/MinaProtocol/mina/blob/a3661e44e01b2c400d6eb5ac254c6ab7a91b3623/src/lib/crypto/kimchi_bindings/wasm/src/plonk_proof.rs#L612 to return maybe_proof.map_err(|str| str.into()) (or something like that), which will make it return the error as a JS exception

Additionally, https://github.com/MinaProtocol/mina/blob/a3661e44e01b2c400d6eb5ac254c6ab7a91b3623/src/lib/crypto/kimchi_bindings/wasm/src/plonk_proof.rs#L585

[nicc]

@nicc chat to Jo about whether zkApps Prod Eng. should be doing this

[nicc]

For now zkApps Product should hold off and not implement this. It's likely to be a crypto thing. Will confirm

[jasongitmail]

@nicc Following up on your last comment. I believe the comment is out of date and Product Eng can pursue this, is that your current understanding too?

[jasongitmail]

@mitschabaude thinks this can likely be closed. Will confirm with crypto team first

[mitschabaude]

The line Err(JsValue::from_str(err.to_string())) makes wasm-bindgen throw a string. It's definitely better to throw a JS Error, which panic! seems to do as well. So we should do something like Err(JsError::from(...))

[mitschabaude]

This is how it should be done:

return match maybe_proof {
    Ok(proof) => ...,
    Err(err) => Err(JsError::from(err))
}

[mitschabaude]

Or like this:

Err(str) => Err(JsError::new(str)),