Chore/migrate to file data source and fix request requester

[Harman-singh-waraich]

builds upon #27

closes #28

With this change the request.requester will be set to requestInfo.party.requester , similar for request.challenger.

Rationale

RequestInfo stores the parties [none, requester, challenger] from the msg.sender in the txn.

https://github.com/kleros/tcr/blob/72e547ea135d839dc5db34e79e9f94f05c6a92bb/contracts/LightGeneralizedTCR.sol#L366C2-L368C1

Whereas if we use event.transaction.from in the subgraph, we get tx.origin(which is not always msg.sender) .

gtcr-subgraph/src/LightGeneralizedTCRMapping.ts

Line 452 in 6494aa9

request.requester = event.transaction.from;

In case of sponsored txn's (by safe) tx.origin can be a random account and not point to the user's safe address,
whereas msg.sender is the user's safe address.

So using msg.sender as the requestee or challenger makes more sense, as that it the account that interacts at contract level.

⚠️ If a user creates a contract to batch the transactions , or interact with the tcr in general, the msg.sender in this case would be the contract. So it is the user's responsibility to make sure they can withdraw the rewards from that contract, as the rewards will be sent to that contract (requestee at contract level)

[sonarcloud]

Quality Gate failed

Failed conditions
15.1% Duplication on New Code (required ≤ 3%)

See analysis details on SonarCloud