[feature] generate multiple candidates for each agent to extend the solution space

[huangyz0918]

• Generate multiple candidates for the single agent output
• Explore API to rate each solutions and move to the next
• Agent should be able to receive multiple context input (?), or generate single context input and start multiple child agent instances (this can be time-consuming).

[HuaizhengZhang]

Will you try the langraph in this feature?

https://www.kaggle.com/code/jinssaa/agent-system-langgraph-vllm-elasticsearch-qwen