Add more info to configurator.render failed

Created by: jozo

When you make a typo in path to a configurator you get only generic error message. The error message should be more descriptive.

Example:

        gcp_metadata:
          type: tosca.nodes.Root
          interfaces:
            Standard:
              create:
                implementation: gcp/helpers.py#WrongName

Error message:

 UNFURL  ERROR  configurator.render failed