CLI to generate iOS/Android bindings without creating rust project

[vivianjeng]

Problem

Now users need to go through mopro init, mopro build to generate MoproiOSBindings/MoproAndroidBindings
but if we just need bindings in existing projects (e.g. Anon Aadhaar)
we can have something like mopro bindgen to output just MoproiOSBindings/ MoproAndroidBindings

Details

mopro bindgen

• platforms: ios/android
• proving systems: circom/halo2
• adapters: rust-witness/witnesscalc + arkworks/rapidsnark (could be an advanced feature)
• input circuits dir: e.g.test-vectors/circom
• (optional) output folder: e.g. ../AnonAadhaariOSBindings

Acceptance criteria

Without running mopro init and mopro build, just runnnig mopro bindgen to generate MoproiOSBindings/MoproAndroidBindings
so the mopro bindgen can be written as a shell script in e.g. anon-aadhaar-react-native
the shell script would be like

#!/bin/sh

# install CLI
git clone https://github.com/zkmopro/mopro
cd mopro/cli
cargo install --path .
cd ../..

# generate bindings
mopro bindgen --platform ios --prover circom --adapters witnesscalc,rapidsnark --keys test-vectors/circom --output AnonAadhaariOSBindings
mopro bindgen --platform android --prover circom --adapters witnesscalc,rapidsnark --keys test-vectors/circom --output AnonAadhaarAndroidBindings

# replace bindings
cp -r AnonAadhaariOSBindings/* ios/AnonAadhaariOSBindings/
cp -r AnonAadhaarAndroidBindings/uniffi/* android/src/main/java/uniffi
cp -r AnonAadhaarAndroidBindings/jniLibs/* android/src/main/jniLibs