Currently all API errors (4xx and 5xx) are exposed identically: `BadStatus` https://github.com/Deepomatic/deepomatic-client-python/blob/3640becf728fb0be861e8a50e6e448dd8faecf49/deepomatic/http_helper.py#L185-L186 We should at least distinguish between 4xx and 5xx. Later we could do some retry on 5xx, cf #17