…entPoint incase of listener error (#120)

Moved and reorganized rollforward logic to improve readability and maintainability. Adjusted handling of currentPoint updates and debug logs to streamline the functionality across different era types.

…to prevent block loss

  * Add requestedPoint field to ChainsyncAgent for tracking unconfirmed blocks
  * Add confirmBlock() method to complete two-phase commit after successful block processing
  * Update onRollForward to set requestedPoint instead of immediately updating currentPoint
  * Implement LIFO listener execution order in Agent class for fail-fast semantics
  * Update N2NChainSyncFetcher to confirm blocks before requesting next message
  * Fix same synchronization issue in reactive BlockStreamer implementation
  * Add Byron block support with proper absolute slot calculation
  * Add comprehensive JavaDoc explaining the two-phase commit pattern
  * Add integration tests for disconnection/reconnection scenarios
  * Add logging for intersection found events to aid debugging

  This fixes the critical issue where blocks could be lost during network disconnections
  when ChainSync would update currentPoint before BlockFetch confirmed successful
  block retrieval. The two-phase commit ensures at-least-once delivery semantics.

…blockfetch

 Implement two-phase commit for ChainSync/BlockFetch synchronization to prevent block loss

Extended `N2CVersionTableConstant` to include V19 and V20 with corresponding version data maps. Updated `HandshakeSerializers` to handle additional data items for N2N protocol, enabling peer sharing and query support for protocol versions V11 and above.

Introduced PeerSharing protocol capabilities including message types, agent, state handling, and serializers. Implemented `PeerDiscoveryIT` integration tests to validate peer sharing and discovery functionalities.

Peer Sharing N2N mini protocol (Merge to 0.3.x)