Implement a check error handling with webook middleware

[JohnathonBowers]

Additional context from Samuel:

What we need is to show a check error. We can investigate how to properly show the error sent by the middleware in something more concise. Can you review this?

The comment had do do with an error that was thrown in changeset.controllers.js:

[BigSamu]

The complete context of this is in this thread. Pull request #41 was approved to not postpone the merging of new features in code.

Still, it is suggested that the code review in PR be solved in this issue.