Changes to the op-node

Unlike standard OP-stack L2s, Facet op-node does not have the responsibility to act as a sequencer. Facet transactions sequencing order is determined by the order in which transactions and events are submitted on Ethereum, and blocks are created by facet node (a different component from op-node, included in a separate scope). Therefore, op-node only has read access to op-geth. The most substantial changes made to op-node have been made to enable op-node to work in this read-only fashion.