### Search before asking - [x] I searched in the [issues](https://github.com/apache/flink-agents/issues) and found nothing similar. ### Description 1. Provide built-in actions `chat_model_action` and `tool_call_action` like python. 2. Provide built-in ReAct Agent api in Java. ### Are you willing to submit a PR? - [x] I'm willing to submit a PR!
