Create a new /status route in aggregator

[jpraynaud]

Why

We need to create a status page on the aggregator that displays basic information which will be used in particular by the explorer.

What

Create a /status route that displays the aggregator status with the following information:

• Epoch (epoch service)
• Cardano era (epoch service)
• Mithril era (epoch service)
• Cardano node version (static)
• Aggregator version (static)
• Protocol parameters (epoch service)
• Next protocol parameters (epoch service)
• Total signers (epoch service)
• Total next signers (epoch service)
• Total stakes signers (epoch service)
• Total next stakes signers (epoch service)
• Adoption rate (% stake of Cardano in Mithril / % SPOs of Cardano in Mithril) (epoch service)

How

• Compute the Cardano era with the chain observer:
  • In the Pallas observer, with the queries_v16::get_current_era function and Era type
  • In the Cardano CLI observer (use the query tip command and read the era field)
• Record in epoch service the new information:
  • Cardano era
  • Mithril era
  • Total SPOs (with StakeDistributionService)
  • Total stake (with StakeDistributionService)
• Create new /status route that displays the status in aggregator
  • Epoch
  • Cardano era
  • Mithril era
  • Cardano node version
  • Aggregator version
  • Protocol parameters
  • Next protocol parameters
  • Total signers
  • Total next signers
  • Total stakes signers
  • Total next stakes signers
  • Total SPOs in Cardano
  • Total stake in Cardano
• Update OpenAPI specs

Later

• Latest imported block number
• Latest immutable file number