Add whole flow example to backend examples

[enricobottazzi]

It would be cool to add the whole flow to backend/examples

It should involve:

• Message signatures to build csv file.
• Snapshot generation
• Proof of Address ownership generation and submission to smart contract
• Proof of Solvency generation and submission to smart contract
• Proof of Mst Inclusion generation
• Proof of Mst Inclusion verification (user side)

Ideally, the example should contain as few lines of code as possible, as all these actions should be abstracted by the backend APIs. This exercise can also inform a better design of the APIs if needed.

[enricobottazzi]

@sifnoc after #152 is merged

I guess that according to the modification we can provide in the example both

• Proof of Mst Inclusion Verification (user side - performed locally using the Verification Key)
• Proof of Mst Inclusion Verification (user side - performed interacting with the view function of the Summa Smart Contract)

[sifnoc]

Related Message signatures to build csv file. task, Ensure that the Ethereum addresses in the file adhere to the checksum format

[enricobottazzi]

#152 (comment)

I think that the new example flow will just need to interact with AddressOwnership and Round objects. Therefore we can make the Snapshot struct as private.

[sifnoc]

• Message signatures to build csv file.
• Snapshot generation
• Proof of Address ownership generation and submission to smart contract
• Proof of Solvency generation and submission to smart contract
• Proof of Mst Inclusion verification (user side - locally using given Verification Key)
• Proof of Mst Inclusion Verification (user side - performed interacting with the view function of the Summa Smart Contract)