Review the tx format in the database

[rllola]

Currently a tx is saved like this

{
  key: '15aa1367992d2004e31881e8f538583709f282c89f6acdd79d4e0d284c4eefee00000000',
  value: {
    id: '15aa1367992d2004e31881e8f538583709f282c89f6acdd79d4e0d284c4eefee',
    version: 1,
    txInCount: 1,
    txIns: [ [Object] ],
    txOutCount: 2,
    txOuts: [ [Object], [Object] ],
    locktime: 3621196,
    size: 226
  }
}

The txInCount and txOutCount are redundant information here as we cna query the length of the arrays for txins and txouts.

We probably also want the block hash info for each tx or at least the height.