Decide "genesis hash" based on configuration

[SebastienGllmt]

Right now there is no concept of a "genesis hash" in Paima (prevBlockHash is just null)

The only similar concept we have is to hash the configuration, but that requires:

• unify the configuration file systems into one (right now we have 3 which overcomplicates things)
• have a way to properly define fields that affect determinism (see Prevent changes to the funnel configuration that can break determinism #398)
• figure out how updating the configs (or game updates in general) affect the block hash (ex: every new update is kind of like a new genesis block for the new era. This is similar to other chains like Cardano where every hardfork is considered a new genesis block)