Use Block Range Merkle roots to sign Cardano transactions

[jpraynaud]

Why

In order to provide faster signature of the Cardano transactions, we need to use Block range Merkle trees roots stored in the databases of the signer and aggregator.

What

Adapt signature process to use Block Ranges Merkle roots to sign Cardano transactions.

[!WARNING] As the current beacon system is based upon the immutable file number, we will use the latest complete block range for an immutable number as a convention.

How

• [ ] Compute the maximum block range to retrieve given the immutable file number in the beacon (requires query on the store) (in common)
• [ ] Create and implement a Block Range Merkle root retriever given a specific block range (in common)
• [ ] Use the Block Range Merkle root retriever in the signable builder to create the signature for the Cardano transactions (in common)
• [ ] Add the Block range Merkle root retriever to the dependency builders of signer and aggregator