Co-authored-by: clabby <ben@clab.by>

An old an unused script for fetching withdrawals
is updated to instead submit pending withdrawals.

op-proposer: Move to shared signer setup & simplified init

This removes the NewL2OutputSubmitterWithSigner function and places
the old NewL2OutputSubmitter code inside the main function.

op-service: Migrate tx manager package

fix batch-deriv-chain.svg

This places the txmgr package in the op-service folder instead of
the op-proposer folder. This removes the proposer for being a dependency
of the batcher. The txmgr code is shared code so it makes more sense to
be there.

feat(e2e): Garbage batch test

feat: l1 and l2 source validation

fix spec/assets/engine.svg

whoops