Implement Cardano Blocks and Transactions in WASM client

[jpraynaud]

Why

The WASM Mithril client should implement functions to list and get blocks and transactions snapshots, and to certify a transaction hash list or a block hash list.

What

Implement the new functions to list and get blocks and transactions snapshots, and to certify a transaction hash list or a block hash list in the WASM Mithril client API.

How

• Adapt the mithril-aggregator-fake to handle the new types of data
• Transactions (suffixed with _v2):
  • Add a function to list transactions snapshots
  • Add a function to get details about a transaction snapshot
  • Add a function for generation/verification of a proof for a list of transactions
  • Add tests that call these functions in ci-test using the mithril-aggregator-fake
• Blocks:
  • Add a function to list block snapshots
  • Add a function to get details about a block snapshot
  • Add a function for generation/verification of a proof for a list of blocks
  • Add tests that call these functions in ci-test using the mithril-aggregator-fake

[jpraynaud]

Hi @leepl37! Would you be interested to work on this issue?