add feedback and feedback_task with cli

[wenzhe-log10]

• Python example

python examples/feedback/simple_feedback.py

• CLI
  create feedback task:

$ log10 feedback-task create --name "test_task_cli" --task_schema '{
        "type": "object",
        "properties": {
          "feedback": {
            "type": "string",
            "enum": ["😀", "😬", "😐", "🙁", "😫"]
          }
        },
        "required": ["feedback"]
    }'

create feedback:

log10 feedback create --task_id daa9e648-b0ab-4da0-9d3c-7e9396ea24ae --values '
  {
    "feedback": "😀"
  }' --completion_tags_selector "give_me_feedback"