[BUG] Data model is lost for python generator when http code is not in 2XX

Created by: lsoica

Description

In the endpoint.handlebar , if the http code is not in the 2xx range, an exception is thrown: https://github.com/OpenAPITools/openapi-generator/blob/master/modules/openapi-generator/src/main/resources/python/endpoint.handlebars#L395

The ApiException implementation only keeps the http message as a plain binary string: https://github.com/OpenAPITools/openapi-generator/blob/master/modules/openapi-generator/src/main/resources/python/exceptions.handlebars#L93

From here on, the model corresponding to the OpenAPI schema of the response in case of a 5xx code for example, is lost.

Is this on purpose? Or maybe I'm doing something wrong ?