AddGenesisAccount create genesis account into `account` and `account_balance` table.

AddGenesisNextNodeAdmission create genesis next node admission timestamp.

GetGenesisNodeRegistrationTx given a genesisEntry, returns a nodeRegistrationTransaction for genesis block.

GetGenesisTransactions return list of genesis transaction to be executed in the very beginning of running the blockchain.

NewMempoolService returns an instance of mempool service.