add a endpoint that always fails and a default endpoint

[jdkandersson]

Applicable spec: N/A

Overview

Introduces a new endpoint that always returns a failure response to be used for testing and a default endpoint that can be used for any other events.

Rationale

Artificially generating a failure in repo-policy-compliance is complex, the new endpoint makes it easy to simulate a failure.The default endpoint can be used for any other events so that we can support all GitHub events.

Module Changes

Introduced new endpoints to the flask blueprint

Checklist

• The contributing guide was applied
• The documentation is generated using src-docs
• The PR is tagged with appropriate label (urgent, trivial, complex)
• Version has been incremented