Refactor endpoint service

[AdamVig]

The endpoint service currently abstracts the use of the database service. Because of this, all of the parameters passed to endpoint service methods are all passed to the database service.

This is an example of the "Middle Man" code smell. To fix it, one can use Remove Middle Man.

A better pattern would be to pass a query from the database service to the endpoint service, which would reduce the signature of every endpoint service call to just a single query parameter.