* op-program: Store created blocks to avoid needing to re-execute them.

Since op-program always creates a new block via engine_forkChoiceUpdated/engine_getPayload and then immediately sends the same block back to engine_newPayload to be imported, store the created block to the database without updating the chain head, so the engine_newPayload method is a no-op instead of having to execute the transactions again.

* op-program: Add test that created block is not reprocessed on import (#12402)

Also fixes differences in block hash for created payloads when using non-op stack chains.