Automate ERPC deployments

[ylembachar]

Set up a GitHub Actions workflow to automate deployments for ERPC. The workflow should:

• Allow manual deployment to Chiado after merging changes into main
• Allow manual deployment to Mainnet after a successful Chiado deployment and testing

[blockchainluffy]

We can do similar system as we have for explorer, meaning, staging branch for chiado deployments and main for mainnet.