Feature Request: allow a callback function to be passed as the function used in the human input tool

[tomlynchRNA]

i.e allow users to replace this function:

crewAI/src/crewai/agents/executor.py

Line 298 in 3d52575

def _ask_human_input(self, final_answer: dict) -> str:

I would change the contents to pull the human input from another system instead of just calling input(). Happy to make a PR, shouldn't be a huge change. Would this be something that would be accepted?