default traceback not helpful in case of server errors

[FelixSchwarz]

If the server responds with a non-200 response, openapi3 produces an exception which is not really helpful. It would be nice if the default traceback contained the server response body (in this case "Request body must not be empty")

Traceback (most recent call last):
  File "client.py", line 33, in <module>
    result = api.call_post_greeting(parameters={'name': 'foo'})
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "…/venv/lib64/python3.12/site-packages/openapi3/openapi.py", line 256, in __call__
    return self.operation(self.base_url, *args, security=self.security, **kwargs)
              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "…/venv/lib64/python3.12/site-packages/openapi3/paths.py", line 359, in request
    raise UnexpectedResponseError(result, self)
openapi3.errors.UnexpectedResponseError: Unexpected response 400 from post_greeting (expected one of 200, no default is defined)

str(exc) returns UnexpectedResponseError('Unexpected response 400 from post_greeting (expected one of 200, no default is defined)') so that would be nice to see also for uncaught exceptions.