Produce metadata with storage layout

[seanyoung]

This will make it possible to walk storage and dump the entire state

[leyafo]

How to parse the storage data like ethereum getStorageAt? What can I do for contribution?

[seanyoung]

@leyafo sorry I missed your comment, @LucasSte reminded me.

The storage data layout is very blockchain dependant, and meta-data needs to be generated for each.

For Parity Substrate, metadata is produced for most data types here https://github.com/hyperledger-labs/solang/blob/main/src/abi/substrate.rs#L367-L388

For ewasm, we need to generate metadata like the storageLayout in https://docs.soliditylang.org/en/v0.8.12/using-the-compiler.html#compiler-api, and then pass this into getStorageAt api call.

For Solana, a new metadata format (probably very similar to the ewasm target) needs to be defined, and then an new api defined for @solana/solidity.

Please let me know if you get stuck and I aim to respond much quicker next time.