* fix: openai response should contains `model`
- Update model attributes in `claudeHandler` for `relay-claude.go`
- Implement model type for fullTextResponse in `relay-gemini.go`
- Add new `Model` field to `OpenAITextResponse` struct in `relay.go`
* chore: set model name response for models
---------
Co-authored-by: JustSong <songquanpeng@foxmail.com>