WIP: Mirgate core sensors to use new sensor interface

@Kami @manasdk I don't like that we have to wrap these inside 'if' block. There are some sensors that poll. There are some sensors that are passive/push sensors. Events get pushed to them (webhooks) and timer just requires scheduler to be running. So this poll/poll interval is not suited for passive sensors. I don't have a solution in mind. Perhaps we can rename 'poll' to 'run' and if poll_interval is not specified, we call 'run' only once at the beginning?