Add an API debug mode

[zepich]

When you develop a new API client or integration, finding the reason for a problem can be challenging. Right now, the API does not explain why a verification didn't work so that an attacker cannot find the real issue.

For this, the idea is to add a debug mode with which the API will tell you more details about the verification process to understand better why the verification failed.

Required features

• Add an option to enable the debug mode for a project
• Collect and add the debug information in a good, explainable format to the response of the API

Origin

Issue #122