YNU-48: Create a package for contract bindings

[alessio]

Task List

• Create pkg/bindings/README file
• Create pkg/bindings/ibalance_checker package
• Create pkg/bindings/ideposit package
• Create pkg/bindings/ierc20 package
• Deploy smart contracts
• Deposit broker funds
• Write migration guide (e.g. the Viem migration guide)
• Write Changelog
• Add Linea Mainnet support to Clearnode

This blocks on #299

[dimast-x]

Closing as this is now outdated.