add 'aliases' data as a comma separated list to products.
Bug: https://bugs.launchpad.net/cpc-core/+bug/1550421 This branch introduces a new "aliases" field as a comma separated list of alias in a string json entry.
Its content is as follow: - release codename - the first letter of the release codename - the version number - the aliases "lts" and "default" if the current active LTS - "devel" if the current development release