This PR introduces a few changes with respect to payload verification in fcu and new payload requests:
* First of all, it undoes the `verifyPayloadAttributes(..)` simplification I attempted in #27872.
* Adds timestamp validation to fcu payload attributes [as required](https://github.com/ethereum/execution-apis/blob/main/src/engine/cancun.md#specification-1) (section 2) by the Engine API spec.
* For the new payload methods, I also update the verification of the executable data. For `newPayloadV2`, it does not currently ensure that cancun values are `nil`. Which could make it possible to submit cancun payloads through it.
* On `newPayloadV3` the same types of checks are added. All shanghai and cancun related fields in the executable data must be non-nil, with the addition that the timestamp is _only_ with cancun.
* Finally it updates a newly failing catalyst test to call the correct fcu and new payload methods depending on the fork.
lightclient
98eaa57e6f