Validate extradata pre-Holocene in engine_consolidate

I ended up reverting this [b54581d](https://github.com/ethereum-optimism/optimism/pull/17307/commits/b54581dfa78ce5d9b347730030e054425fe3eb43), I didn't want to change the existing behaviour (it broke existing tests). Happy to look again in a followup PR>

_Originally posted by @geoknee in https://github.com/ethereum-optimism/optimism/pull/17307#discussion_r2324994070_

Start by reviewing the reverted commit b54581d from pull request 17307 and locate the engine_consolidate implementation and the existing tests it changed. Compare the pre-Holocene extradata validation behavior with those tests; done means the intended validation is covered without breaking the existing behavior.

Written by the indexing model from the issue text.