[DELTA-6933] Drop L3BackfillMapper, update L3BackfillStorage to MetafillerStorage

[calebguy]

Ticket

• Related Linear Ticket: DELTA-6933

What does this PR do?

• Summary:
  Removes unused contracts from the backfill & makes necessary updates to the current backfill contracts

• Key Changes:

  • Removes L3BackfillMapper as it will no longer be used
  • Renames L3BackfillStorage to MetafillerStorage
  • Updates the event emitted in MetafillerStorage, removing the l3BlockNumber & introducing the epochHash
  • Renames the l1EpochBlockNumber to epochNumber in the MetafillerStorage contract
  • Introduces a public variable indexFromBlock & admin only setter setIndexFromBlock which indicates where to begin indexing blocks from
  • Updates related factory contracts & tests

Does this PR introduce any breaking changes (API/schema)?

• Yes/No:
  • Metafiller will be updated to account for the new function signature & contract address

Do any environment variables need to be updated or added before deployment?

• Yes/No:
  • If yes, list the required environment variables and their values, along with descriptions.

How can this PR be tested?

cd metabased-contracts && forge install && forge test

[linear]

DELTA-6933 Update Metafiller Storage contract to add startAtBlock & param changes

Things to change in easier to read format

• Change l1EpochNumber to epochNumber
• Drop l3BlockNumber
• Add epochHash
• Change contract name to MetafillerStorage
• Add variable indexFromBlock and admin only setter

For the contract we should change l1EpochNumbers to just epochNumber, we can get rid of l3BlockNumebrs entirely, we might want to replace l3BlockNumber with epochHash as I think thats used more widely by op-translator.

As suggested by Felipe we could and should add a publicly available getter that is something like indexFromBlock which would allow a person who is setting up their own indexer to be able to see easily which blokc they should start indexing from. This should only be writeable by the admin.

Maybe we can rename the contract something different as well like MetafillerStorage or something similar.

[gustavoguimaraes]

LGTM

[gustavoguimaraes]

Nice! I am working on the workshop for the Edge City and will need the change in the factory contract here.

Thus I am merging this. Thanks