Add genesis files and balances

[Alann27]

Summary

1. Added functionality to index genesis file.
2. Added functionality to track balance of accounts by denom without needing to perform an aggregate.

Details

1. Added GENESIS_FILE_PATH env to .env.sample and is being used to specify the path of the genesis file.
2. Added testnet.json and localnet.json files to genesis directory.
3. Added handleGenesis to the mappings datasources.
   1. In this handle we are reading the genesis file, saving the accounts specified in it and then saving the balances using the following entities: NativeBalanceChange, GenesisBalance and BalanceOfAccountByDenom.
4. Created types/genesis.ts file with types related to the genesis index process.
5. Added BalanceOfAccountByDenom entity type to the schema.graphql. This entity is beind used to save the coin (denom and amount) of an account without performing any aggregate, it can be queried with just a select.
6. Added GenesisFile entity type to save the processed genesis file(s).
7. Removed commented fields on schema.graphql.
8. Added getEventId function to utils to create the id of the events.
9. Added updateAccountBalance to update the balance of accounts using BalanceOfAccountByDenom entity.

Issue

The balances of the genesis accounts were not right because the genesis files was not being indexed.

Type of change

Select one or more:

• New feature, functionality or library
• Bug fix
• Code health or cleanup
• Documentation
• Other (specify)

Sanity Checklist

• I have tested my changes using the available tooling
• I have commented my code
• I have performed a self-review of my own code; both comments & source code
• I create and reference any new tickets, if applicable
• I have left TODOs throughout the codebase, if applicable

[jorgecuesta]

lgtm. Please @Olshansk @bryanchriswhite remember the scope of this genesis parsing is only for accounts. Later we will expand to save from Genesis the state of Applications, Gateways, Suppliers, etc.

[bryanchriswhite]

Amazing @Alann27, thanks! 🚀 This is great to see. 💪

I just had a couple more small suggestions (one of which is cleaning up my own mistake 😅). Otherwise, this LGTM! 🚢