Stopping existing containers when docker-compose changes after a rerun of stack_box

[sonagarajan]

We lose track of existing containers when we rerun stackbox keeping the existing containers. Two possible solutions.

Also results in listing these existing containers as up in the final stackbox.sh logs

Add a check before new docker compose generation for existing containers with the prefix stackbox_ in their names to stop before bringing up new ones
Or add a stackdown sh to bring down containers