Optimize the existing database queries

[bogdanbujdea]

In certain cases, data is aggregated and this might lead to slow response times for the API. These endpoints should be identified and move the data in new tables where it can be retrieved faster.

Example: The /winners endpoints which now try to retrieve the data from the "winners" table. If the data isn't there, it will aggregate it and then put it in the table so it will be available for the next requests.