Represent empty responses as None #770

When I specify no content for a response, I would expect to generate a sync method and async method that returns None.

Currently, I work against an api that has a few endpoints returning no data (that could be with status code 200 or status code 204).
Example:

   "/something" : {
      "patch" : {
        ...
        "responses" : {
          "200" : {
            "description" : "something"
          }
        }
      }
    }

When I generate a client with this project, this endpoint will not have a sync or async method, but only the sync_detailed and async_detailed. This works, but it looks weird because for all other methods I use sync/async. I would be great to have them implemented to return None (like a void/unit method in python).

I think, the problem manifests here:

The sync method is only generated if the return type is not any - which makes sense. But I think, the return type here is not actually Any - but None. The response type comes from here:

Here is a link with documentation on handling empty responses and any type: https://swagger.io/docs/specification/data-models/data-types/

According to that, the difference is having either no content field for empty responses and having a content field defined with an empty object for any type.