Handle 'rolled back' offchain (L2) transaction/transfer.

[jacque006]

Related https://github.com/thehubbleproject/hubble-contracts/issues/548

What's wrong

If a user submits an L2 transfer that is successfully submitted in a batch on L1, but is later rolled back after a successful dispute of that batch or a batch before it, it will be difficult for that L2 user to determine what has happened and why that transfer did not go through.

How we can fix it

In syncing nodes, track and provide details on 'rolled back' L2 transfers. This can be done by keeping historical records on what L1 confirmed batches have been rolled back by a dispute.