Modify how a collection is moved between repositories when a state change occurs.

After deprecation per repo https://github.com/pulp/pulp_ansible/pull/392 lands in pulp_ansible:

Replace the use of galaxy_ng task add_content_to_repo with new pulp_ansible copy task
Replace the use of galaxy_ng task remove_content_from_repo with new pulp_ansible task add_and_remove and specify the remove_units and no add_units (no longer needed)