Use Cannon for Deployments

[kaze-cow]

Description

In order to improve multi-network multi-repository deployments of CoW protocol, we are switching to using Cannon. This PR officially deprecates any previous deployment systems and output files, and replaces them with Cannon. It also includes all the appropriate documentation for continued maintenance and usage of cannon, and

General changes:

• Add hardhat-cannon and @usecannon/cli to package.json
• Add cannonfile.toml with a configuration that replicates the existing smart contracts structure
• Add EIP173.sol and Proxy.sol to the repository--required for the correct proxy implementation as was previously provided by hardhat-deploy
• Add a CI job to validate the successful cannon build and the recorded artifacts are matching
• Remove old deployment files: deployments/, networks.json
• Remove old deployment system src/deploy
• Update README.md explaining how things work now.

Test Plan

• Build the cannon package as instructed in the README
• Ensure that the output contract addresses are as expected
• Verify that the CI works as expected.

Related

cow-deployments repository