Reorg Sequencer based on observed batches submitted on L1

[snario]

Work done in the past (i.e., see ethereum-optimism/go-ethereum#300) added support to geth to re-org the chain based on transactions submitted to the L1 canonical transaction chain. We'd like to revive this work.

[smartcontracts]

Going to be handled as part of Bedrock. Closing since there's no real value in having this issue open here when the work is already scoped out and included as part of the requirements for Bedrock. I'd transfer this over to optimistic-specs but I believe it's already reflected there.