Add OP Holocene fork

[emlautarom1]

Resolves #7760

Changes

• Support OP Holocene

Types of changes

What types of changes does your code introduce?

• Bugfix (a non-breaking change that fixes an issue)
• New feature (a non-breaking change that adds functionality)
• Breaking change (a change that causes existing functionality not to work as expected)
• Optimization
• Refactoring
• Documentation update
• Build-related changes
• Other: Description

Testing

Requires testing

• Yes
• No

If yes, did you write tests?

• Yes
• No

Notes on testing

Added tests that cover all new LOCs. Manual testing is still required.

Documentation

Requires documentation update

• Yes
• No

I don't think it's a requirement to update the docs.

Requires explanation in Release Notes

• Yes
• No

We should communicate that Nethermind is ready to support the new OP fork.

Remarks

Initially, only Sepolia timestamps are included for both Optimism and Base since those are the only ones currently known at this time.

[emlautarom1]

I don't see much point in having IOptimismSpecHelper for starters, but could replace this ISpecProvider with IOptimismSpecHelper, and replace releaseSpec.GetSpec(parent).IsOpHoloceneEnabled with helper.IsHolocene(parent).

If we don't use IOptimismSpecHelper then its additions related to Holocene are essentially dead code (no usages).

[LukaszRozmej]

I still don't like the hidden dependency and side effect with BaseFeeCalculator.
I would change exceptions handling.

[LukaszRozmej]

This could fail and throw exception

[emlautarom1]

I think that at that point we've already validated the attributes so there should not be a risk of exceptions (unless I'm missing something):

1. We validate attributes in

nethermind/src/Nethermind/Nethermind.Merge.Plugin/Handlers/ForkchoiceUpdatedHandler.cs

Lines 89 to 95 in 4013c7a

	public async Task<ResultWrapper<ForkchoiceUpdatedV1Result>> Handle(ForkchoiceStateV1 forkchoiceState, PayloadAttributes? payloadAttributes, int version)
	{
	Block? newHeadBlock = GetBlock(forkchoiceState.HeadBlockHash);
	return await ApplyForkchoiceUpdate(newHeadBlock, forkchoiceState, payloadAttributes)
	?? ValidateAttributes(payloadAttributes, version)
	?? StartBuildingPayload(newHeadBlock!, forkchoiceState, payloadAttributes);
	}

2. Then we use the IPreparationService in StartBuildingPayload

nethermind/src/Nethermind/Nethermind.Merge.Plugin/Handlers/ForkchoiceUpdatedHandler.cs

Line 327 in 4013c7a

payloadId = _payloadPreparationService.StartPreparingPayload(newHeadBlock.Header, payloadAttributes);

3. Eventually, OptimismPayloadPreparationService.ImproveBlock is called:

nethermind/src/Nethermind/Nethermind.Merge.Plugin/BlockProduction/PayloadPreparationService.cs

Lines 74 to 85 in 4013c7a

	public string StartPreparingPayload(BlockHeader parentHeader, PayloadAttributes payloadAttributes)
	{
	string payloadId = payloadAttributes.GetPayloadId(parentHeader);
	if (!_payloadStorage.ContainsKey(payloadId))
	{
	Block emptyBlock = ProduceEmptyBlock(payloadId, parentHeader, payloadAttributes);
	ImproveBlock(payloadId, parentHeader, payloadAttributes, emptyBlock, DateTimeOffset.UtcNow);
	}
	else if (_logger.IsInfo) _logger.Info($"Payload with the same parameters has already started. PayloadId: {payloadId}");
	return payloadId;
	}

nethermind/src/Nethermind/Nethermind.Optimism/OptimismPayloadPreparationService.cs

Lines 45 to 46 in 4013c7a

	protected override void ImproveBlock(string payloadId, BlockHeader parentHeader,
	PayloadAttributes payloadAttributes, Block currentBestBlock, DateTimeOffset startDateTime)

[emlautarom1]

I think we could remove this static class altogether by leveraging extension methods but for now I'll leave it as it is to avoid more diffs.