[Feature]: Add label lookup for inputs and outputs in tasks

[creatorrr]

🔖 Feature description

Right now, inputs and outputs both are a list[Any]. We recently updated the typespec for all steps to optionally include a label?: string.

Goal is to enable lookup for labels in inputs and outputs so for example:

main:
- evaluate:
    a: 1
    b: 2
  label: example
- tool: print
  arguments:
    hello: outputs[“example”].a
    there: outputs[0].b

🎤 Why is this feature needed ?

No response

✌️ How do you aim to achieve this?

No response

🔄️ Additional Information

No response

👀 Have you spent some time to check if this feature request has been raised before?

• I checked and didn't find similar issue

Are you willing to submit PR?

None