fix: Fixed runtime error occurring when calling v2 API on v1 serve

[vlastahajek]

Closes #216

Proposed Changes

Properly handling unexpected responses in generated code

Checklist

• CHANGELOG.md updated
• Rebased/mergeable
• A test has been added if appropriate
• Tests pass
• Commit messages are in semantic format

[sranka]

Nice work, requiring >=300 status code for a successful API response does the fix. It might have been the case that the error body was exposed from the generated API intentionally, for example here: https://github.com/influxdata/influxdb-client-go/blob/master/api/buckets.go#L148 . I guess that such bodies are now lost and different errors are thrown, don't they?

[vlastahajek]

Added default switch clause is executed only if none of defined response types are not handled, e.g. for mentioned CreateBucket:

    switch {
	case strings.Contains(rsp.Header.Get("Content-Type"), "json") && rsp.StatusCode == 201:
		var dest Bucket
		if err := json.Unmarshal(bodyBytes, &dest); err != nil {
			return nil, err
		}
		response.JSON201 = &dest

	case strings.Contains(rsp.Header.Get("Content-Type"), "json") && rsp.StatusCode == 422:
		var dest Error
		if err := json.Unmarshal(bodyBytes, &dest); err != nil {
			return nil, err
		}
		response.JSON422 = &dest

	case strings.Contains(rsp.Header.Get("Content-Type"), "json") && true:
		var dest Error
		if err := json.Unmarshal(bodyBytes, &dest); err != nil {
			return nil, err
		}
		response.JSONDefault = &dest

	// Fallback for unexpected error
	default:
		if rsp.StatusCode > 299 {
			return nil, &ihttp.Error{StatusCode: rsp.StatusCode, Message: rsp.Status}
		}
	}