Extend bootstrap parser for snapshot delegations and stake pools

[buddhisthead]

What

As a developer working on "boot from snapshot", I require a new callback for the Mark/Set/Go snapshot data contained in the stage delegation and pool sections.

Acceptance Criteria

• Parser correctly reads the delegation and pool data of each of the Mark/Set/Go snapshot sections
• Parameters are added for the snapshot callback that utilize existing datatypes (no adapters required)
• Sample test driver is extended to prove parsed values
• Bootstrapper callback API is updated with new parameters with a TODO marker for future work