[#20] Make it possible to manually add storage annotations

Description

Problem: currently ContractRegistry can only print contracts without storage annotations. Ideally we want to generate annotations in Lorentz, but the proper solution for it will take some time to be merged and we need this feature already.

Solution: extend ContractInfo with storage annotations, consider them in runContractRegistry.

Related issue(s)

Relates to #20 (closed)

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