Cursors Should be Encoded On Server Side

Problem: Currently, the integration tests do not enforce the requirement that the cursors returned by the query/kinds and query/records endpoints are encoded on the server side. The integration tests are not assuming the returned cursors are encoded; they are manually encoding the cursors (example). I think we only expect clients to be using cursors to pass back into a subsequent request to these endpoints. Therefore, it makes sense to require encoding on the server-side so that the cursors returned to clients are ready to use.

This change would require the CSPs verifying that their code is encoding the cursor on the server side and then updating the integration tests so that they assume the cursor they get in the response body is encoded already.