For example, erigon on devnet8 marked a block as bad due to
"mdbx_cursor_open: cannot allocate memory":
```
[INFO] [09-12|04:57:36.041] [NewPayload] Handling new payload height=171035 hash=0x321dea00c4853ee354bebaf8aef3e63fbe06c4508271c0db4c92b0f087aedc3b
171034
[WARN] [09-12|04:57:36.069] Could not validate block err="[3/7 BlockHashes] table: Header, mdbx_cursor_open: cannot allocate memory, stack: [kv_mdbx.go:1057 kv_mdbx.
go:1069 kv_mdbx.go:1077 memory_mutation.go:473 memory_mutation.go:502 etl.go:123 etl.go:96 block_writer.go:40 stage_blockhashes.go:49 default_stages.go:457 sync.go:425 sync.go:258 s
tageloop.go:414 backend.go:476 fork_validator.go:250 fork_validator.go:156 ethereum_execution.go:151 execution_client.go:51 chain_reader.go:252 engine_server.go:741 engine_server.go
:235 engine_server.go:600 value.go:586 value.go:370 service.go:224 handler.go:494 handler.go:444 handler.go:392 handler.go:223 handler.go:316 asm_amd64.s:1598]"
[WARN] [09-12|04:57:36.069] ethereumExecutionModule.ValidateChain: chain is invalid hash=0x321dea00c4853ee354bebaf8aef3e63fbe06c4508271c0db4c92b0f087aedc3b
```
With this PR blocks are marked as bad only on genuine protocol errors.
* (EIP-4399) MixDigest is utilized for RANDOM
* Add GetTd to ChainHeaderReader
* Remove unused VerifyHeaders from consensus consensus
* Introduce params.MaxGasLimit
* Serenity engine: fall back to eth1 engine before the Merge
* Serenity engine in CreateConsensusEngine
* ethOne -> eth1Engine
