Decentralize the configuration parameters of Mithril networks

## Why

We need to decentralize the configuration parameters of the Mithril network (protocol parameters and certification parameters - signed entity types and their specific configuration parameters e.g. `cardano_transactions_signing_config`). In a first phase, we have implemented a full synchronization of the network based on the leader aggregator, and we now want the configuration to be stored on the Cardano chain.

## What

Decentralize the configuration parameters of the Mithril protocol by storing them on chain.

## Later
- Rollout plan for deprecation/removal of legacy synchronization of signers and aggregators
- Delete the epoch settings route in aggregator after removal of legacy synchronization of signers and aggregators
- Simplifiy the database structure in aggregator after removal of legacy synchronization of signers and aggregators