Extend parser to include protocol params

[lowhung]

Context

As a developer of the Boot from Snapshot feature, I need the Streaming Snapshot parser to extract protocol parameters from the NewEpochState. These parameters are required by the Parameters State module to initialize correctly at bootstrap rather than replaying governance outcomes from genesis.

Problem

The Streaming Snapshot parser doesn't currently extract protocol parameters. According to the CDDL spec, these are located in gov_state within the NewEpochState at:

• gs_current_pparams - current active protocol parameters
• gs_previous_pparams - previous epoch's parameters
• gs_future_pparams - scheduled future parameter changes

Path: NewEpochState → epoch_state → ledger_state → utxo_state → gov_state

Acceptance Criteria

• Streaming Snapshot parser extracts gs_current_pparams from gov_state
• Streaming Snapshot parser extracts gs_previous_pparams from gov_state
• Streaming Snapshot parser extracts gs_future_pparams from gov_state
• Parsed parameters are available for downstream consumers during bootstrap

Definition of Done

• Protocol parameters parsed from snapshot and accessible to Parameters State module
• Parameters State can initialize from snapshot without replaying governance history