Is your feature request related to a problem? Please describe.
Passing a message to converse() would make it possible to contribute more complex skills to the project (sometimes, raw utterances are not enough). This changes cannot be simply implementer in an overridden skill converse() since this method is called by the SkillManager.

Describe the solution you'd like
In SkillManager.handle_converse_request(), add a function signature check to pass either an overridden converse or the default one.

Describe alternatives you've considered
Digging through the message stack directly in skill.converse() but that requires more complex changes.

Additional context
This feature is awaiting for a PR review.