Added real top data for qaforums once unique identities support has been added.
Added steps to remove all dbs.
Added new JSON files with data about studies correct results.
Improved testing in test_data_source_api.py for studies.
Report filenames when JSON files are different, or a JSON file does not exists.
Don't print data in different fields in JSON if the field is avoided for comparing.
[contributors_new_gone] Completed the implementation for result.
[studies] When no data available return None.