Evaluate "soft delete" of workspaces and templates at the database level

[sei-jbooz]

Template disks are already "soft deleted" -- the VMDKs aren't removed from the vSphere datastore when the template is deleted in our deployment. Might be worth also considering a "soft delete' of templates and workspaces at the database level to prevent accidental data loss. The DB in our largest deployment isn't very big (300MBs), so the additional space used likely wouldn't make much of an impact.