Update the CatalogD demo script to use source-code in the operator-controller repo

See that we have the script: https://github.com/operator-framework/operator-controller/blob/main/catalogd/hack/scripts/demo-script.sh

We need to update it to the script from the operator-controller release instead.

PS: we might need to do a release with catalogD inside of the operator-controller to do this. 
