Flag's data records status in evaluation results

[iamafanasyev]

In our setup we decided not to log flag evaluation on server as it has several negative effects on our analytics due to infrastructure config (cache, retries, etc.), but to report actual client state on the client side. Already present data records facility fits perfectly for that purpose (to manage the data for analytics). It would be nice to extend evalResult data type with something like this:

dataRecords:
  description: flag's data records status.
  type: boolean
  x-omitempty: true

so you could optimize "client data recording" based on actual evaluation results