To easily automate cleanup of (large) process work directories without losing important tower metadata files, like the nf-.. files used for Reports, it would be good to be able to store them in a different path (e.g. a different prefix on S3). Right now they are both directly in 'workDir', making it impossible to use simple AWS lifecycle rules to cleanup process work folders without also deleting the "nf-*" files and breaking the Report links from the tower front-end