Feature/blip 6 test suite shield contract

[biscuitdey]

Description

• Deployment of the shield contract on test blockchain and addition of the verifier
• Reimplemented set up of the Agreement state
• Rewrote tests for the mock zk component

Related Issue

Issue is related to BLIP-6 project

Motivation and Context

Deploys the shield contract on a test blockchain (Ganache) and stores the Agreement merkle tree root on-chain.

How Has This Been Tested

Testing environment:

• Run the go service for generating the zk circuit under the "zkcircuits" component
• Run a local test blockchain (Ganache)
• Use npm run test in the "bpi-monolith-test-suite" folder to run all the tests (including zk test suite)

Screenshots (if appropriate)

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)
• [x] Request to be added as a Code Owner/Maintainer

Checklist

• [x ] My code follows the code style of this project.
• [ ] My change requires a change to the documentation.
• [ ] I have updated the documentation accordingly.
• [x] I have added tests to cover my changes.
• [x] All new and existing tests passed.
• [x] I commit to abide by the Responsibilities of Code Owners/Maintainers.