Better way to detach node

[take-cheeze]

When removing multiple nodes from the graph we need to update GetLiveNodes or check whether node is detached.
It's OK for now since point that needs checking or update is only here.
Though it may need to do either in other places in the future and it's not a good thing to do every time.

• Update live nodes list after every node mutation
• Keep the inputs/outputs of node and remove detached in correct timing(May need some modification in ONNX generator)