beacon/engine: add shouldOverrideBuilder to payload envelope

This PR makes EIP-4788 work in the engine API and miner. It also fixes some bugs related to 
EIP-4844 block processing and mining. Changes in detail:

- Header.BeaconRoot has been renamed to ParentBeaconRoot.
- The engine API now implements forkchoiceUpdatedV3
- newPayloadV3 method has been updated with the parentBeaconBlockRoot parameter
- beacon root is now applied to new blocks in miner
- For EIP-4844, block creation now updates the blobGasUsed field of the header

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Co-authored-by: Marius van der Wijden <m.vanderwijden@live.de>
Co-authored-by: Felix Lange <fjl@twurst.com>

This change implements "EIP 4788 : Beacon block root in the EVM". It implements version-2 of EPI-4788, main difference being that the contract is an actual contract rather than a precompile, as in #27289.

This is a spin-out from the EIP-4844 devnet branch, containing just the Engine API modifications
and nothing else. The newPayloadV3 endpoint won't really work in this version, but we need the
data structures for testing so I'd like to get this in early.
Co-authored-by: Marius van der Wijden <m.vanderwijden@live.de>

* beacon/types: add beacon chain data types

* beacon/merkle: added comments

* go.mod: cleanups

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Co-authored-by: Péter Szilágyi <peterke@gmail.com>

This ensures the "withdrawals" field will always be present in responses
to getPayloadBodiesByRangeV1 and getPayloadBodiesByHashV1.

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Co-authored-by: Felix Lange <fjl@twurst.com>

The method `GetPayloadBodiesByRangeV1` now returns "-38004: Too large request" error if the requested range is too large, according to spec
Co-authored-by: Martin Holst Swende <martin@swende.se>

This change will break one hive test, but pass another and it will be the better way going forward

This PR moves core/beacon to beacon/engine so that beacon-chain related code has its own top level package which also can house the the beacon lightclient-code.