Improve ApiResponse implementation for QueryResult documentation

Summary:
To avoid a too magic method, we explain comprehensively the error codes
through two examples, the current one for SELECT, a new one for INSERT.

The II and III code comments cases were swapped.

Test Plan: no op

Reviewers: dereckson

Reviewed By: dereckson

Differential Revision: https://devcentral.nasqueron.org/D1952