Draft: Deprecate CERN mounts fact

The CERN mounts fact is completely redundant given the core mountpoints fact.

It is in use in a number of locations. Grep suggests

• hostgroups/hg_tapeserver/manifests/init.pp ai/it-puppet-hostgroup-tapeserver!17
• hostgroups/hg_eos/manifests/private/diskserver.pp ai/it-puppet-hostgroup-eos!1064
• hostgroups/hg_afssrv/manifests/spare.pp ai/it-puppet-hostgroup-afssrv!55
• hostgroups/hg_afssrv/manifests/include/collectd/vicep_full.pp ai/it-puppet-hostgroup-afssrv!55
• modules/castor/manifests/diskserver.pp ai/it-puppet-module-castor!27