Map Txs: create a mechanism to map these to our orders in the database

[matt-auckland]

• Check Tx addresses against the database and map Txs to orders
  • valid Tx must match order value +/- x%
  • method returns an object:

    {
    validTxs: [
    {
      Tx,
      Order 
    }
    ],
    invalidTxs: [
    {
      Tx,
      Order : Order || false (no matching order found)
    }
    ] 
    }

• Recheck continuously using the preflight loop