Store block, tx infos

[Atralupus]

Mimir already contains multiple pieces of code that sync data from the node and holds information like accounts and avatars, making it a great candidate to replace 9cscan.

To replace 9cscan Cloud, the following additional data is required
- Block information
- Transaction (tx) information
- Transaction status information

We need to collect this data from {headless}/graphql/explorer, store it in MongoDB, and expose it via an API.

query getBlock($index: ID!) {
  blockQuery {
    block(index: $index) {
      raw
    }
  }
}