Add Labels to ChainParameters to Enable Hardforks via Single Timestamp

[LuisDi98]

This PR introduces functionality to allow grouped EIP timestamps (e.g., dencun, cancun) in ChainParameters. This simplifies the process of activating multiple EIPs simultaneously through a single label, while preserving the ability to handle individual EIP timestamps.

Fixes #7738

Changes

• Added DencunTransitionTimestamp and CancunTransitionTimestamp to ChainParameters class.
• Implemented ValidateNoTimestampConflicts to detect and validate timestamp conflicts between labels and individual EIPs.
• Updated ChainSpecParamsJson to support grouped label serialization/deserialization.
• Added tests in ChainParametersTests to verify label functionality and conflict detection.

Types of Changes

What types of changes does your code introduce?

• New feature (a non-breaking change that adds functionality)

Testing

Requires testing

• Yes

If yes, did you write tests?

• Yes

Notes on testing

Added unit tests in ChainParametersTests to verify:

• Setting and getting label timestamps.
• Conflict detection for mismatched individual EIP timestamps.
• Valid behavior when all timestamps match.

Documentation

Requires documentation update

• No

Requires explanation in Release Notes

• Yes

Release Notes:

• Added support for grouped EIP timestamps (dencun, cancun) in ChainParameters for simplifying hardfork activation.

[LukaszRozmej]

We need to support all hardforks

[LukaszRozmej]

We should have a helper method to have such comparisions as we will do it for every hardfork.

[LukaszRozmej]

Potentially we could have _dencunTransitionTimestamp and individual EIP's out of sync, so maybe always calculate it and don't have a separate field?

[LukaszRozmej]

Potentially we could have _dencunTransitionTimestamp and individual EIP's out of sync, so maybe always calculate it and don't have a separate field? Then you also don't need Validate methods

[LukaszRozmej]

You could potentially use more declarative style of Expression Api to map individual properties to Hardfork property, that might be useful outside of this class too?